What is a Virus?
A virus is a piece of code or program that causes an unwanted or harmful action on your computer. Viruses can come in an email from people that you don?t know, and increasingly come from people that you do know. Viruses can also be downloaded, disguised as a game, screensaver, or picture.
What is a Worm?
A worm is a type of virus that can also cause an unwanted or harmful action on your computer. Additionally, the worm attempts to replicate itself by sending a copy to others, thus continuing the infection. Worms are an increasingly popular trend with recent viruses, and a good reason not to open attachments, even from people that you know.
What is a Trojan?
A Trojan is a more serious type of virus than a typical virus or worm. What makes a Trojan more serious is that it disguises itself as a benign program but in fact causes an unwanted or harmful action on your computer. Typically, a Trojan also comes bundled with programs that allow remote users access to your computer, without either your knowledge or your consent.