<human>:  What is the difference between a virus and a computer worm?
<bot>: The main difference between a virus and a computer worm is that a virus attaches itself to other programs or files on a computer, whereas a computer worm is a standalone malicious program which replicates itself over a network, using security vulnerabilities in other computers in order to spread itself. A virus will typically cause harm to the computer, such as corrupting or deleting files, while a computer worm will cause problems in the form of excessive resource usage and bandwidth consumption by replicating itself across systems.