Trojan HorseA destructive program that masquerades as a benign application. Unlike viruses, Trojan horses do not replicate themselves but they can be just as destructive. One of the most insidious types of
Trojan horse is a program that claims to rid your computer of viruses but instead
introduces viruses onto your computer.
Viruses and WormsA program or piece of code that is loaded onto your computer without your knowledge and
runs against your wishes. Viruses can also replicate themselves. All computer viruses are manmade. A simple virus that can make a copy of itself over and over again is relatively easy to produce. Even such a simple virus is dangerous because it will quickly use all available memory and bring the system to a halt. An even more dangerous type of virus is one capable of transmitting itself across networks and bypassing security systems.
Since 1987, when a virus infected ARPANET, a large network used by the Defense Department and many universities, many anti-virus programs have become available. These programs periodically check your computer for the best-known types of viruses.
Some people distinguish between general viruses and worms. A worm is a special type of virus that can replicate itself and use memory, but cannot attach itself to other programs.
Hope this helps. By the way, these definitions are from
http://www.webopedia.com This is a good site with definitions of computer-related terms. Good place to check to find out what something is.
Best...Larry
