Answer Description
A virus is a type of malware that infects another program (typically an exe/executable) and has the ability to spread itself to other systems. Both viruses and worms may have the ability to replicate themselves with or without user intervention. They key difference is that a worm is a standalone program while a virus infects an existing program, for example a critical Windows executable.
Wikipedia
A computer virus is a type of computer program that, when executed, replicates itself by modifying other computer programs and inserting its own code When this replication succeeds, the affected areas are then said to be "infected" with a computer virusVirus writers use social engineering deceptions and exploit detailed knowledge of security vulnerabilities to initially infect systems and to spread the virus The vast majority of viruses target systems running Microsoft Windows, employing a variety of mechanisms to infect new hosts, and often using complex anti-detection/stealth strategies to evade antivirus software Motives for creating viruses can include seeking profit (e
Computer_virus - Wikipedia, the free encyclopedia