What is a Computer Virus?

A virus is an independent program that reproduces itself. It can attachitself to other programs and make copies of itself (i.e., companion viruses).It can damage or corrupt data, or lower the performance of your system by usingresources like memory or disk space. A virus can be annoying or it can cost youlots of cold hard cash. A virus is just another name for a class of programs.They do anything that another program can. The only distinguishingcharacteristic is the program has ability to reproduce and infect other programs.Is a computer virus similar to a human virus?

Computer viruses are small software programs that are designed to spread from one computer to another and to interfere with computer operation.
A virus might corrupt or delete data on your computer, use your e-mail program to spread itself to other computers, or even erase everything on your hard disk.
Viruses are often spread by attachments in e-mail messages or instant messaging messages. That is why it is essential that you never open e-mail 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.
Viruses also spread through downloads on the Internet. They can be hidden in illicit software or other files or programs you might download.


To help avoid 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.