A worm is a type of malicious software (malware) designed to spread itself across networks without the need for human interaction or attaching to other programs. Once it infects a system, a worm replicates itself and seeks out other devices to infect, often exploiting vulnerabilities in software or network configurations. Unlike viruses, worms operate independently, and their primary goal is to propagate as widely as possible. They can cause significant damage by consuming network bandwidth, corrupting data, or delivering additional malicious payloads.