What’s antivirus?

Viruses are bits of computer code that are designed to perform a specific purpose, as well as usually designed to propagate from one computer to another on a network. Anti-virus software is designed to detect these bad-behaving bits of code and prevent them from doing what they were originally designed to do. Anti-virus can run on the PCs themselves and can also run on a firewall scanning network traffic, or on a mail server scanning all of the attachments on emails. Ideally it downloads signatures which are basically lists of known virus behaviours on a regular scheduled basis, allowing it to detect new viruses soon after they are released.