- A virus is a piece of computer code that attaches itself to a program
or file so it can spread from computer to computer, infecting as it
- A worm, like a virus, is designed to copy itself from one computer
to another, but it does so automatically by taking control
of features on the computer that can transport files or
information. Once you have a worm in your system it can travel alone. A
great danger of worms is their ability to replicate in great volume.