What is a worm (computer virus)?

We're doing a paper in my Language Arts class on something that interests us, and I chose technology, and have decided to write my article on computer viruses. I've done some research, but can anyone tell me what a "worm" is?What is a worm (computer virus)?
There actually is a subtle difference between a worm and a computer virus. You could say that a worm is a type of virus. A virus is merely any program that can install itself ("infect") another computer and, as part of its routine, send itself off and infect other computers on a network. A worm is a type of virus that exploits a vulnerability in the operating system itself.



For instance, many viruses infect a computer after the user has accessed a specific infected file. Trojan horses are programs that seem to be useful, such as a new wordprocessor, but actually install malicious software. Worms, however, do not actually require anything from the user in order for them to infect a computer. They are the most dangerous, and the first to get patched.



To help with your research, some good buzzwords are: malware, trojan, phishing, spear phishing, zero day exploit, stuxnet, buffer overflow attack, cross site scripting, and sequel injection.What is a worm (computer virus)?
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. This is due to security shortcomings on the target computer. Unlike a computer virus, it does not need to attach itself to an existing program. Worms almost always cause at least some harm to the network, even if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a targeted computer.What is a worm (computer virus)?
Worms are malicious programs that make copies of themselves over and over, on the local drive, network, email, or Internet. In other words, the sole purpose of a worm is to reproduce, unlike a virus which attempts to infect, i.e. embed its code into, other files.
A worm is a bad thing that messes up your computer.