What is the primary distinction between a virus and a worm?

The primary distinction between a virus and a worm lies in the way they propagate. A virus requires a host file to spread, which means it attaches itself to a legitimate program or file. When the infected host file is executed, the virus activates and can then spread to other files and programs on the same system or via infected files shared with others. This dependency on a host file is a critical characteristic that defines how viruses operate.

In contrast, worms are capable of replicating themselves independently without needing to attach to a host file. They can spread across networks on their own, often exploiting vulnerabilities in networked devices.

Understanding this distinction helps in recognizing how to defend against these threats, as the strategies for preventing virus infections can differ from those used to mitigate worm outbreaks.