1. What is a Computer? Computer generally means a programmable machine. The two principal characteristics of a computer are: it responds to a specific set of instructions in a well-defined manner and it can execute a prerecorded list of instructions (a program).

2. Modern Computers Defined Modern computers are electronic and digital. The actual machinery — wires, transistors, and circuits — is called hardware; the instructions and data are called software.

3. What is a Network? A group of interconnected (via cable and/or wireless) computers and peripherals that is capable of sharing software and hardware resources between many users.

4. LAN vs. WAN A Local Area Network (LAN) consists of two or more computers connected together in a building or home using software and hardware. A Wide Area Network (WAN) is a network that spans a large geographical area, the most common example being the Internet.

5. What is a Server? In a technical sense, a server is an instance of a computer program that accepts and responds to requests made by another program; known as a client. Less formally, any device that runs server software could be considered a server as well. Servers are used to manage network resources. For example, a user may setup a server to control access to a network, send/receive e-mail, manage print jobs, or host a website.

6. What is a Server? (continued) Some servers are committed to a specific task; often referred to as dedicated. As a result, there are a number of dedicated server categories, like print servers, file servers, network servers and database servers.

7. What is a Server? (continued) Because they are commonly used to deliver a services that are required constantly, most servers are never turned off. Consequently, when servers fail, they cause the network users or company many problems. To alleviate these issues, servers are commonly high-end computers setup to be fault tolerant.

8. What is a Computer Virus? Through the course of using the Internet and your computer, you may have come in to contact with computer viruses. Many computer viruses are stopped before they can start, but there is still an ever growing concern as to what do computer viruses do and the list of common computer virus symptoms. A computer virus might corrupt or delete data on your computer, use your email program to spread itself to other computers, or even erase everything on your hard disk.

9. What is a Computer Virus? (Cont’) Computer viruses are often spread by attachments in email messages or instant messaging messages. That is why it is essential that you never open email attachments unless you know who it's from and you are expecting it. Viruses can be disguised as attachments of funny images, greeting cards, or audio and video files. Computer viruses also spread through downloads on the Internet. They can be hidden in illicit software or other files or programs you might download.

10. What is a Computer Virus? (Cont’) To help avoid computer viruses, it's essential that you keep your computer current with the latest updates and antivirus tools, stay informed about recent threats, run your computer as a standard user (not as administrator), and that you follow a few basic rules when you surf the Internet, download files, and open attachments. Once a virus is on your computer, its type or the method it used to get there is not as important as removing it and preventing further infection.

11. How to remove a computer Virus? http://www.wikihow.com/Remove-a-Virus