my fishes

Fish: "Add a touch of nature to your page with these hungry little fish. Watch them as they follow your mouse hoping you will feed them by clicking the surface of the water."

hahaist... Grabeh, halos perme na lang jud nako masugat.an iyang ngan... God, please help me to overcome this... habang tumatagal, di ko na maintindihan bakit ganun.... Awh??? pagblogge rmo please! hehehe

Quiz 9 - Computer Security and Safety, Ethics, and Privacy

1. Define the term, computer security risks, and briefly describe the types
of cybercrime perpetrators: hacker, cracker, script kiddie, corporate spy,
unethical employee, cyberextortionist, and cyberterrorist. 

Answer:

Computer security is a branch of computer technology known as Information Security as applied to computers and networks. The objective of computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to remain accessible and productive to its intended users. 

Cybercrime Perpetrators

Hacker refers to a computer programmer who is able to create usable computer programs where none previously existed. 

Cracker is a variation of hacker, with the analogy equal to a safe cracker. Some individuals use the term cracker in an attempt to differentiate from the honorable computer programmer definition of hacker.

Script kiddy is an individual who executes computer scripts and programs written by others. Their motive is to hack a computer by using someone else’s software. Examples include password decryption programs and automated access utilities. 


Corporate Spy - have excellent computer and networking skills and are hired to break into a specific computer and steal its proprietary data and information.

Unethical employee - break into their employers' computer for a variety of reasons. Some simply want to exploit security weakness.

Cyberextortionist - is someone who uses e-mail as a vehicle for extortion. These perpetrator s send an organization a threatening e-mail message indicating they will expose confidential information, exploit a security flaw, or launch an attack that will compromise the organization s network - if they are not paid of a sum of money.

Cyber-terrorist - a programmer who breaks into computer systems in order to steal or change or destroy information as a form of cyber-terrorism.

 
2. Describe various types of Internet and network attacks (computer viruses,
worms, Trojan horses, rootkits, botnets, denial of service attacks, back
doors, and spoofing), and identify ways to safeguard against these attacks,
including firewalls, intrusion detection software, and honeypots. 

 Answer:

A computer virus is a computer program that can copy itself and infect a computer. The term "virus" is also commonly but erroneously used to refer to other types of malware, including but not limited to adware and spyware programs that do not have the reproductive ability.

A computer worm is a self-replicating malware computer program, which uses a computer network to send copies of itself to other nodes (computers on the network) and it may do so without any user intervention.

Trojan horse, or Trojan, is a destructive program that masquerades as an application. The software initially appears to perform a desirable function for the user prior to installation and/or execution, but (perhaps in addition to the expected function) steals information or harms the system. Unlike viruses or worms, Trojan horses do not replicate themselves, but they can be just as destructive.

3. Discuss techniques to prevent unauthorized computer access and use 

Answer:

Some ways to prevent anuathorized computer access and use by disabling the file, folder and printer sharing on internet connection. use a user name with unique combination of characters that identifies user and make a password this is a private combination of characters associated with the user name that allows access to computer resources. aside from that ypou can also use a biometric device this is to authenticates person's identity using personal characteristics like fingerprints, hand geometry, voice, signature and iris.

4. Identify safeguards against hardware theft and vandalism

 Answer:

Hardware theft is the act of stealing computer equipment. Hardware vandalism is the act of defacing or destroying computer equipment. The best preventive measures against hardware theft and vandalism are common sense and a constant awareness of the risk. Physical devices and practical security measures, such as locked doors and windows, can help protect equipment. Passwords, possessed objects, and biometrics can reduce the risk of theft or render a computer useless if it is stolen.

5. Explain the ways software manufacturers protect against software piracy. 

 Answer:

Software piracy is the unauthorized and illegal duplication of copyrighted software. To protect themselves from software piracy, manufacturers issue a license agreement and require product activation.

6. Discuss how encryption works, and explain why it is necessary 

 Answer:

Encryption prevents information theft and unauthorized access by converting readable data into unreadable characters. To read the data, a recipient must decrypt, or decipher, it into a readable form. An encryption algorithm, or cypher, converts readable plaintext into unreadable cipher text. Encryption is used to protect information on the Internet and networks.

7. Discuss the types of devices available that protect computers from system failure 

 Answer:

A system failure is the prolonged malfunction of a computer. A common cause of system failure is an electrical power variation such as noise, an undervoltage, or an overvoltage. A surge protector, also called a surge suppressor, uses special electrical components to smooth out minor noise, provide a stable current flow, and keep an overvoltage from reaching the computer and other electronic equipment. An uninterruptible power supply (UPS) contains surge protection circuits and one or more batteries that can provide power during a temporary loss of power.

8. Explain the options available for backing up computer resources.

 Answer:

A backup is a duplicate of a file, program, or disk that can be used to restore the file if the original is lost, damaged, or destroyed. Users can opt for a full backup or a selective backup. Some users implement a three-generation backup policy that preserves three copies of important files: the grandparent, the parent, and the child. Others use RAID or continuous backup. Most operating systems and backup devices include a backup program.

9. Identify risks and safeguards associated with wireless communications. 

 Answer:

A backup is a duplicate of a file, program, or disk that can be used to restore the file if the original is lost, damaged, or destroyed. Users can opt for a full backup or a selective backup. Some users implement a three-generation backup policy that preserves three copies of important files: the grandparent, the parent, and the child. Others use RAID or continuous backup. Most operating systems and backup devices include a backup program.

10. Discuss ways to prevent health-related disorders and injuries due to
computer use. 

 Answer:

A computer-related repetitive strain injury (RSI) can include tendonitis and carpal tunnel syndrome (CTS). Another health-related condition is eyestrain associated with computer vision syndrome (CVS). To prevent health-related disorders, take frequent breaks, use precautionary exercises and techniques, and use ergonomics when planning the workplace. Computer addiction occurs when the computer consumes someone's entire social life.

11 Recognize issues related to information accuracy, intellectual property
rights, codes of conduct, and green computing. 

 Answer:

Computer ethics govern the use of computers and information systems. Issues in computer ethics include the responsibility for information accuracy and the intellectual property rights to which creators are entitled for their works. An IT (information technology) code of conduct helps determine whether a specific computer action is ethical or unethical. Green computing reduces the electricity and environmental waste while using a computer.

12 Discuss issues surrounding information privacy, including electronic
profiles, cookies, spyware and adware, spam, phishing, privacy laws, social
engineering, employee monitoring, and content filtering.

Answer:

Information privacy is the right of individuals and companies to deny or restrict the collection and use of information about them. Issues surrounding information privacy include the following. An electronic profile combines data about an individual's Web use with data from public sources, which then is sold. A cookie is a file that a Web server stores on a computer to collect data about the user. Spyware is a program placed on a computer that secretly collects information about the user. Adware is a program that displays an online advertisement in a banner or pop-up window. Spam is an unsolicited e-mail message or newsgroup posting sent to many recipients or newsgroups at once. Phishing is a scam in which a perpetrator attempts to obtain personal or financial information. The concern about privacy has led to the enactment of many federal and state laws regarding the disclosure of data. As related to the use of computers, social engineering is defined as gaining unauthorized access or obtaining confidential information by taking advantage of the trusting human nature of some victims and the naivety of others. Employee monitoring uses computers to observe, record, and review an employee's computer use. Content filtering restricts access to certain materials on the Web.  

Quiz 8 - Database Management

1. Define the term, database, and explain how a database interacts with data and information.

A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality (for example, the availability of rooms in hotels), in a way that supports processes requiring this information (for example, finding a hotel with vacancies).

2. Describe file maintenance techniques (adding records, modifying records, deleting records) and validation techniques.


File Maintenance  refers to the procedures that keep data current.
- Adding Records users add new records to a file when they obtain new data Disc
- Modifying Records users modify a record to correct inaccurate data or update old data
- Deleting Records When a record no longer is needed, a user deletes it from a file
- Validation Techniques compares data with a set of rules or values to find out if the data is correct  

• Alphabetic/Numeric check
• Range check
• Consistency check
• Completeness check
• Check digit
• Other checks

3. Discuss the terms character, field, record, and file.

Character - Eight bits grouped together in a unit form a byte, and each byte represents a single character, which can be a number, letter, space, punctuation mark, or other symbol.

Field - is a combination of one or more related characters and is the smallest unit of data a user accesses.

Record - is a group of related fields.

File - is a collection of related records stored on a storage medium.

4. Discuss the functions common to most database management systems: data dictionary, file retrieval and maintenance, data security, and backup and recovery.

Data dictionary, or metadata repository, as defined in the IBM Dictionary of Computing, is a "centralized repository of information about data such as meaning, relationships to other data, origin, usage, and format.

File maintenance - refers to the procedures that keep data current. It include adding records when new data is obtained, modifying records to correct inaccurate data or to update old data with new data, and deleting records when they no longer are needed.  

Backup - is the copy of the database.

Recovery Utility - uses the logs and/or backups to restore the database.

5. Differentiate between a file processing approach and the database approach.

File processing approach - each department or area within an organization has its own set of data files.

Database Approach -Many programs and users share the data in a database. Reduces data redundancy, improves data integrity, shares data, permits easier access, and reduces development time.

6. Describe characteristics of relational, object-oriented, and multidimensional databases.

Relational Database - is a database that stores data in tables that consist of rows and columns. Each row has a primary key and each column has a unique name.

Object - oriented database (OODB) - stores data in objects. An object is an item that contains data, as well as the actions that read or process the data.

Multidimensional database - stores data in dimensions and can store more than two dimensions of data.

7. Explain how to access Web databases.


Web database  database you can access through web by filing in a form in a web page.
A Web database links to a form on a Web page. To access data in a Web database, you fill on the form or enter search text on a Web page. A Web database usually resides on a database server, which is a computer that store and provides access to a database

8. Define the term, computer security risks, and briefly describe the types of cybercrime perpetrators: hacker, cracker, script kiddie, corporate spy, unethical employee, cyberextortionist, and cyberterrorist.

Computer security is a branch of computer technology known as Information Security as applied to computers and networks. The objective of computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to remain accessible and productive to its intended users. 

Cybercrime Perpetrators

Hacker refers to a computer programmer who is able to create usable computer programs where none previously existed. 

Cracker is a variation of hacker , with the analogy equal to a safe cracker. Some individuals use the term cracker in an attempt to differentiate from the honorable computer programmer definition of hacker.

Script kiddy is an individual who executes computer scripts and programs written by others. Their motive is to hack a computer by using someone else’s software. Examples include password decryption programs and automated access utilities.

Corporate Spy - have excellent computer and networking skills and are hired to break into a specific computer and steal its proprietary data and information.

Unethical employee - break into their employers' computer for a variety of reasons. Some simply want to exploit security weakness.

Cyberextortionist - is someone who uses e-mail as a vehicle for extortion. These perpetrator s send an organization a threatening e-mail message indicating they will expose confidential information, exploit a security flaw, or launch an attack that will compromise the organization s network - if they are not paid of a sum of money.

Cyber-terrorist - a programmer who breaks into computer systems in order to steal or change or destroy information as a form of cyber-terrorism.

9. Identify database design guidelines and discuss the responsibilities of database analysts and administrators.

Database Analysts and Database Administrators are responsible for managing and coordinating all database activities. 

Database Analysts (DA) - focuses on the meaning and usage of data. The DA decides on the placement of fields, defines the relationships among data, and identifies user's access privilege.

Database Administrators (DBA) requires a more technical inside view of the data. The DBA creates and maintains the data dictionary, manages data security, monitors database performance, and checks backup and recovery procedures

oh my day!

whaheheehehehehhe

Quiz 7 Communications and Networks

1. Discuss the purpose of the components required for successful communications (sending device, communications device, communications channel, and receiving device) and identify various sending and receiving devices.

answer:
         

A sending device initiates the transmission of data, instructions, and information while a receiving device accepts the items transmitted.

	Microcomputers, minicomputers, and mainframes all can serve as sending and receiving devices.
	Besides, Internet appliances and Web enabled handheld computers and devices (e.g., cellular telephones and pagers) can also serve as sending and receiving devices.

2. Describe these uses of computer communications: wireless messaging services, wireless Internet access points, cybercafes, global positioning systems, collaboration, groupware, voice mail, and Web services

answer:
   

A sending device initiates the transmission of data, instructions, and information while a receiving device accepts the items transmitted. All types of computers and mobile devices serve as sending and receiving devices in a communications system. This includes mainframe computers, servers, desktop computers, notebook computers, Tablet PCs, smart phones, portable media players, and GPS receivers.

3. List advantages of using a network, and differentiate among LANs, MANs, and WANs.

answer:
         Following are some of the advantages of computer networks.

• File Sharing: allows file sharing and remote file access. 
• Resource Sharing: an important benefit of a computer network. F
• Increased Storage Capacity: As there is more than one computer on a network which can easily share files, the issue of storage capacity gets resolved to a great extent.
• Increased Cost Efficiency: Computer networks resolve this issue as the software can be stored or installed on a system or a server and can be used by the different workstations.

          Local Area Network (LAN) 

l          Network in limited geographical area such as home or office building   

              - Wireless LAN (WLAN)

l    - Metropolitan area network (MAN) connects LANs in city or town.

    

          Wide Area Network (WAN)

           Network that covers large geographic area using many types of media    

              - Network that covers large geographic area using many types of media

l

    - Internet is world’s largest WAN

MetropolitanArea Network(MAN)  

Covers a metropolitan area- such as a city or the suburbs of a city.
- You can think of them as between what a LAN and WAN would be.
- They span a much larger geographical area than LANs,
but do not often surpass the limits of a metropolitan area.

- MANs are generally good for businesses and organizations that have
multiple locations around a city. A bank may also take advantage of a MAN. 

4. Differentiate between client/server and peer-to-peer networks, and describe how a P2P network works.

answer:

         On a client/server network, one or more computers acts as a server, sometimes called a host computer, which controls access to network resources and provides a centralized storage area, while the other computers and devices on the network are clients that rely on the server for resources. 
A peer-to-peer network is a simple network that typically connects fewer than 10 computers that have equal responsibilities and capabilities. P2P is an Internet peer-to-peer network on which users access each other's hard disks directly and exchange files over the Internet.

5. Describe the various network communications standards: Ethernet, token ring, TCP/IP, Wi-Fi, Bluetooth, UWB, IrDA, RFID, WiMAX, and WAP.

answer:
        
Ethernet- specifies that no central computer or device on the network should control when data can be transmitted.
Token ring- requires devices to share or pass a special signal, called a token.
TCP/IP - divides data into packets.
Wi-Fi-identifies any network based on the 802.11 standards for wireless communications. Bluetooth-uses short-range radio waves to transmit data.
UWB-specifies how two UWB devices use short-range radio waves to communicate at high speeds.
IrDA- transmits data wirelessly via infrared light waves.
RFID-uses radio signals for communications.
WiMAX- a network standard developed by IEEE that specifies how wireless devices communicate over the air in a wide area.
Wireless Application Protocol (WAP)- specifies how some mobile devices can display Internet content.

6. Differentiate among a star network, bus network, and ring network.

answer:
             Bus- is one of the most widely used network topologies. A bus network uses a cable to which all the network devices are attached, either directly or through a junction box. The method of attachment depends on the type of bus network, the network protocol, and the speed of the network.
          Star- s arranged in a central structure with branches radiating from it. The central point of the star-structure is called a concentrator, into which plug all the cables from individuals machines. On machine on the network usually acts as the central controller or network server.
          Ring- is a closed network structure in the form of a circle, to which all nodes are connected. Despite misconceptions, there is no physical loop made of the network cable, at least not in the case of the most common form of ring network called Token Ring. The ring name comes from the design of the central network device, which has a loop inside it to which are attached cables for all the devices on the network.

7. Describe various types of lines for communications over the telephone network: dial-up, ISDN, DSL, FTTP, T-carrier, and ATM.

answer:

Analog

- Also called dial-up access, it is both economical and slow. Using a modem connected to your PC, users connect to the Internet when the computer dials a phone number (which is provided by your ISP) and connects to the network. Dial-up is an analog connection because data is sent over an analog,  public telephone network. 

• Typical Dial-up connection speeds range from 2400 bps to 56 Kbps.

ISDN

- Integrated services digital network (ISDN) is an international communications standard for sending voice, video, and data over digital telephone lines or normal telephone wires.

• Typical ISDN speeds range from 64 Kbps to 128 Kbps.
  

DSL

- DSL is also called an always on connection because it uses existing 2-wire copper telephone line connected to the premise and will not tie up your phone as a dial-up connection does. There is no need to dial-in to your ISP as DSL is always on. The two main categories of DSL for home subscribers are called ADSL and SDSL.

FTTP (Fiber-To-The-Premises) Telecom
 

- A broadband local loop configuration involving optical fiber from the edge of the telco or CATV network to the customer premises. A contemporary FTTP loop generally conforms to one of the passive optical network (PON) standards. See also broadband, CATV, local loop, optical fiber, PON, and telco.

T-carrier

- The generic designator for any of several digitally multiplexed telecommunications carrier systems. Note 1: The designators for T-carrier in the North American digital hierarchy correspond to the designators for the digital signal (DS) level hierarchy. 

8. Explain the purpose of communications software.

answer:
            Communication software is used to provide remote access to systems and is also used to exchange messages in text, audio and video format for the purpose of communication. These software send and receive data over telephone lines through modems. The communication software allows computers in different geographical regions to communicate with each other through terminal emulators, file transfer programs, chat and instant messaging programs.

9. Discuss different ways to set up a home network.

answer:

•  Multiple IP addresses: An easy way of getting the second PC online is to install a network card in it, buy a hub, plug both PCs and the cable/DSL modem into the hub, call your ISP and get a second IP address and configure the second PC accordingly.

• Internet Connection Sharing via Software: In this scenario, you install a second network card in the computer that is connected to the Internet, install a network card in the second PC, connect them via a CAT5 cable. You configure the connection between PC 1 and PC 2 as a private network, then install and configure Internet Connection Sharing software (ICS) on PC 1, lastly configure PC 2 to access the Internet via PC 1.  

• Using a hardware router/gateway/firewall device: In this scenario, you install a hardware router/gateway/firewall device, connect the public side to your cable/DSL modem, connect the private side to a hub, connect all PCs to the hub, configure all PCs for your private network.

10. Describe various physical and wireless transmission media: twisted-pair cable, coaxial cable, fiber-optic cable, infrared, broadcast radio, cellular radio, microwaves, and communications satellite.

answer:
        

Twisted-pair cable - consists of one or more twisted-pair wires bundled together.   

Coaxial cable - consists of a single copper wire surrounded by at least three layers: 

• an insulating material 
• a woven or braided metal 
• a plastic outer coating     

Fiber-optic cable - consists of thin strands of glass or plastic that use light to transmit signals.  
Infrared - a wireless transmission media that sends signals using infrared light waves.
Broadcast radio - distributes radio signals through the air over long and short distances.
Cellular radio - a form of broadcast radio that is used widely for mobile communications.
Microwaves -  radio waves that provide a high-speed signal transmission.

Communications satellite - a space station that receives microwave signals from an earth-based station, amplifies the signals, and broadcasts the signals back over a wide area.

11. Describe commonly used communications devices: dial-up modems, digital modems, wireless modems, network cards, wireless access points, routers, and hubs and switches.

answer:
        
Dial-up modem converts digital signals to analog signals and analog signals to digital signals so that data can travel along analog telephone lines.  

Digital modem sends and receives data and information to and from a digital line.

ISDN modem transmits digital data to and from an ISDN line, while a DSL modem transmits digital data to and from a DSL line.  

Cable modem, sometimes called a broadband modem, is a digital modem that sends and receives digital data over the cable television network.  

Wireless modem uses the cell phone network to connect to the Internet wirelessly from mobile computers and devices.  

Network card enables a computer or device that does not have built-in networking capability to access a network.  

Wireless access point allows computers and devices to transfer data wirelessly.  

Router connects multiple computers or other routers together and transmits data to its correct destination on the network.  

Hub or switch is a device that provides a central point for cables in a network.

Quiz 6 - Operating Systems and Utility Programs

1.Define system software and identify the two types of system software.

answer: 

System software is computer software designed to operate the computer hardware and to provide a platform for running application software.

Software is generally divided into: systems software applications software
Systems software are programs which help in the running of a computer system. Some examples are.. disc formatting programs operating system compiler
Applications software are programs which perform specific tasks for the user. Some examples are... word processing software graphics package theatre booking software

2.Briefly describe various server operating systems: Windows Server, UNIX,Linux, Solaris, and NetWare.

answer:
   

Windows Server- a brand name for a group of server operating systems released by Microsoft Corporation. All are part of Microsoft Servers. This brand includes the following software:

• Windows Server 2003
• Windows Server 2008
  • Windows HPC Server 2008, an edition designed exclusively for high-performance computing
  • Windows Server 2008 R2, the current release of Windows Server 2008
• Windows Small Business Server, an operating system based on Windows Server with some integrated Microsoft Servers, for small businesses
• Windows Essential Business Server, a product similar to Small Business Server, but for medium-sized businesses
• Windows Home Server, a home server operating system for file sharing and streaming, automated backups, and remote access
  • Windows Home Server 2011, a home server operating system designed for Small Office/Home Office (SOHO)
• Windows MultiPoint Server, a product allowing multiple simultaneous local users.

UNIX- In addition to being a stand-alone operating system, UNIX also is a server operating system.That is, UNIX is capable of handling a high volume of transactions in a multiuser environment and working with multiple processors using multiprocessing. For this reason, some computer professionals call UNIX a multipurpose operating system because it is both a stand-alone and server operating system. Many Web servers use UNIX as their operating system.

Linux- Some network servers use Linux as their operating system. Thus, Linux also is a multipurpose administrator can configure the network, administer security, run a Web server, and process e-mail. Clients on the network can run Linux, UNIX, or Windows. Distributions of Linux include the Mozilla Web browser. operating system. With Linux, a network

Solaris- Solaris, a version of UNIX developed by Sun Microsystems, is a server operating system designed specifically for e-commerce applications. Solaris manages high-traffic accounts and incorporates security necessary for Web transactions. Client computers often use a desktop program, such as GNOME desktop, that communicates with the Solaris operating system.

NetWare- Novell’s NetWare is a server operating system designed for client/server networks. NetWare has a server portion that resides on the network server and a client portion that resides on each client computer connected to the network. NetWare supports open source software and runs on all types of computers from mainframes to personal computers. 

3.Summarize the features of several embedded operating systems: Windows Embedded CE, Windows Mobile, Palm OS, iPhone OS, BlackBerry, Google Android, Embedded Linux, and Symbian OS.

answer:

Microsoft Windows CE (now officially known as Windows Embedded Compact and previously also known as Windows Embedded CE , and sometimes abbreviated WinCE) is an operating system developed by Microsoft for embedded systems. Windows CE is a distinct operating system and kernel, rather than a trimmed-down version of desktop Windows. It is not to be confused with Windows Embedded Standard which is an NT-based componentized version of desktop Microsoft Windows.

Windows Mobile is a mobile operating system developed by Microsoft that was used in smartphones and mobile devices, but by 2011 was rarely supplied on new phones. The last version is "Windows Mobile 6.5.5"; it is superseded by Windows Phone 7, which does not run Windows Mobile software. Unlike operating systems for desktop computers, it is usually not possible to upgrade the operating system on a Microsoft based mobile phone via official and legal means, even by a later release of the same basic operating system let alone a different one; hardware replacement is the only way for less popular and older devices.

Palm OS (also known as Garnet OS) is a mobile operating system initially developed by Palm, Inc., for personal digital assistants (PDAs) in 1996. Palm OS is designed for ease of use with a touchscreen-based graphical user interface. It is provided with a suite of basic applications for personal information management. Later versions of the OS have been extended to support smartphones. Several other licensees have manufactured devices powered by Palm OS.

iOS (known as iPhone OS before June 2010) is Apple's mobile operating system. Originally developed for the iPhone, it has since been extended to support other Apple devices such as the iPod touch, iPad and Apple TV. Apple doesn't license iOS for installation on third-party hardware. As of May 31, 2011, Apple's App Store contains more than 500,000 iOS applications, which have collectively been downloaded more than 15 billion times. In the last quarter of 2010, it had a 26% share of the smartphone operating system market in terms of units sold, behind Google's Android and Nokia's Symbian.As of May 2010, it accounted for 59% of mobile web consumption—not including the iPad—in North America.

  

BlackBerry is a line of mobile e-mail and smartphone devices developed and designed by Research In Motion (RIM) since 1999.BlackBerry phones function as a personal digital assistant and portable media player. They are primarily known for their ability to send and receive (push) Internet e-mail wherever mobile network service coverage is present, or through Wi-Fi connectivity. They support a large array of instant messaging features, including BlackBerry Messenger.

 Android is a software stack for mobile devices that includes an operating system, middleware and key applications.Google Inc. purchased the initial developer of the software, Android Inc., in 2005.Android's mobile operating system is based on the Linux kernel. Google and other members of the Open Handset Alliance collaborated on Android's development and release. The Android Open Source Project (AOSP) is tasked with the maintenance and further development of Android. Android was listed as the best-selling Smartphone platform world-wide in Q4 2010 by Canalys.

Embedded Linux is the use of Linux in embedded computer systems such as mobile phones, personal digital assistants, media players, set-top boxes, and other consumer electronics devices, networking equipment, machine control, industrial automation, navigation equipment and medical instruments. According to survey conducted by Venture Development Corporation, Linux was used by 18% of embedded engineers.

Symbian is a mobile operating system (OS) and computing platform designed for smartphones and currently maintained by Nokia. The Symbian platform is the successor to Symbian OS and Nokia Series 60; unlike Symbian OS, which needed an additional user interface system, Symbian includes a user interface component based on S60 5th Edition. The latest version, Symbian^3, was officially released in Q4 2010, first used in the Nokia N8. Symbian OS was originally developed by Symbian Ltd.It is a descendant of Psion's EPOC and runs exclusively on ARM processors, although an unreleased x86 port existed.

 

4.Explain the purpose of several utility programs: file manager, search utility, image viewer, uninstaller, disk cleanup, disk defragmenter, backup and restore utilities, screen saver, personal firewall, antivirus programs, spyware and adware removers, Internet filters, file compression, media player, disc burning, and personal computer maintenance.

 answer:
 

A file manager or file browser is a computer program that provides a user interface to work with file systems. The most common operations performed on files or groups of files are: create, open, edit, view, print, play, rename, move, copy, delete, search/find, and modify attributes, properties and permissions. Files are typically displayed in a hierarchy. Some file managers contain features inspired by web browsers, including forward and back navigational buttons.

Search Utility - Ultra File Search is a Search Utility which is able to find quickly Files, Folders and Text on your Local, Network, DVD, CD-ROM, USB Hard or Flash Drives. Ultra File Search allows you to specify several File Mask and multiple Drives and/or Folders at the same time; it is able to sort out files and folders according to their properties (e.g. Modified Date) and find files which contain one or more specific words or sentences.

An image viewer or image browser is a computer program that can display stored graphical image; it can often handle various graphics file formats. Such software usually renders the image according to properties of the display such as color depth, display resolution, and color profile.

An uninstaller, also called a deinstaller, is a utility software designed to remove other software or parts of it from a computer. It is the opposite of an installer.

Disk Cleanup (cleanmgr.exe) is a computer maintenance utility included in Microsoft Windows designed to free up disk space on a computer's hard drive. The utility first searches and analyzes the hard drive for files that are no longer of any use, and then removes the unnecessary files. 

Defragmentation is the process of locating the noncontiguous fragments of data into which a computer file may be divided as it is stored on a hard disk, and rearranging the fragments and restoring them into fewer fragments or into the whole file. Defragmentation reduces data access time and allows storage to be used more efficiently.

backup or the process of backing up refers to making copies of data so that these additional copies may be used to restore the original after a data loss event.Backups have two distinct purposes. The primary purpose is to recover data as a reaction to data loss, be it by data deletion or corrupted data. Data loss is a very common experience of computer users. 67% of internet users have suffered serious data loss. The secondary purpose of backups is to recover data from a historical period of time within the constraints of a user-defined data retention policy, typically configured within a backup application for how long copies of data are required.

A screensaver is a type of computer program initially designed to prevent phosphor burn-in on CRT and plasma computer monitors by blanking the screen or filling it with moving images or patterns when the computer is not in use. Contemporary screensavers are used primarily for entertainment or security.

A personal firewall is an application which controls network traffic to and from a computer, permitting or denying communications based on a security policy.A personal firewall differs from a conventional firewall in terms of scale. Personal firewalls are typically designed for use by end-users. As a result, a personal firewall will usually protect only the computer on which it is installed.

Antivirus or anti-virus software is used to prevent, detect, and remove malware, including but not limited to computer viruses, computer worm, trojan horses, spyware and adware. This page talks about the software used for the prevention and removal of such threats, rather than computer security implemented by software methods.

Spyware is a type of malware that can be installed on computers, and which collects small pieces of information about users without their knowledge. The presence of spyware is typically hidden from the user, and can be difficult to detect. Typically, spyware is secretly installed on the user's personal computer. Sometimes, however, spywares such as keyloggers are installed by the owner of a shared, corporate, or public computer on purpose in order to secretly monitor other users.

Internet filtering refers to blocking undesirable content on the Internet. It helps you filter and deny access to any unwanted material. The person who sets up the filter provides a system to block certain data. It may include advertising, a virus, sexual content, file transfer, or other offensive material. When a user makes a request for a Web page that has been blocked, the Internet filter keeps the request from being completed. It either blocks it completely or redirects it to another location.

data compression, source coding or bit-rate reduction is the process of encoding information using fewer bits than the original representation would use. Compression is useful because it helps reduce the consumption of expensive resources, such as hard disk space or transmission bandwidth. On the downside, compressed data must be decompressed to be used, and this extra processing may be detrimental to some applications.

Media player can refer to:

• Media player (application software)
• Data storage devices that play media and content:
  • HD media player
  • Mobile Digital Media Player (M-DMP)
  • Portable media player

Optical disc authoring, including DVD and Blu-ray Disc authoring (often referred to colloquially as burning), is the process of assembling source material—video, audio or other data—into the proper logical volume format to then be recorded ("burned") onto an optical disc (typically a compact disc or DVD).

Good PC maintenance involves a number of different jobs, from keeping your keyboard and mouse clean, to cleaning up your hard drive by removing temporary files.The frequency of the maintenance will depend on how often the computer is used. Basic maintenance, such as wiping over the keyboard and the screen should be done as often as possible, at least once a week for computers that are used daily.