Anti-virus software is a computer program that can be used to scan files to identify and eliminate computer viruses and other malicious software (malware).
Anti-virus software typically uses two different techniques to accomplish this:
1. The review of records for known viruses through a virus dictionary
2. Identifying suspicious of any computer program that may indicate infection
Most commercial anti virus software uses both approaches, with emphasis on the virus dictionary approach.
Virus dictionary approach
In the virus dictionary approach, when the anti-virus software examines a file, it refers to a dictionary of known viruses that have been identified by the author of anti-virus software.