What are virus scanner definition, DAT or DEF files and why do I need to update them regularly?
Definition files are essentially the instruction set for anti-virus scanners to detect and remove viruses. New viruses are created everyday and scanners rely on definition files to inform them what signatures new viruses leave behind to be detected. It is for this reason that you should check regularly (roughly every 2 weeks) to see if there have been revised definition files for your anti-virus scanner to ensure that it is looking for the most current viruses.
