Computer Virus Definition
If you are looking to protect your PC, you need to learn the jargon for PC security. Here we will look at the definitions of computer virus, trojans and computer worms. Sometimes these terms are used interchangeably, but they are in fact quite distinct.
Computer virus definition
A computer virus is a computer program that can replicate itself and pass from PC to PC. It does this without the knowledge of the user. Many of these programs can cause harm to your machine. In extreme cases they can damage files and cause your whole system to shut down. At the less severe end of the scale they can cause your computer to run slow, and change the position of items on your desktop. One thing that is a defining feature of a computer virus is that it needs a 'host' computer program to transfer from one computer to another. This may occur when a file is transferred around a network, or a computer program is downloaded from the Internet or a file is transferred between computers using a USB or CD.
Computer Worm
A worm is similar to a computer virus but it does not require a host computer program to transfer it from one computer to another. It is self-replicating and can infect a large number of machines in a short space of time. The 'Iloveyou' worm was a well-known example of a worm that became widespread before antivirus software was able a to identify and deal with the threat.
Trojan
Like in the actual story of the Greek Trojan horse, a computer trojan can initially appear to be a useful program. However it can at a latter date release its 'payload' and cause a problem to the running of your computer.
Now that you know the computer virus definitions you will be able to understand the claims made by the various antivirus software companies. It is a very good idea that you get a product that will protect you against each of these different types of security threat.