system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does an antivirus work?
gpt
computer wise -

you have a team of people whose job it is to solely find new viruses and find out what they do and how to identify and remove them.

once this team identifies a virus and how to remove it safely this gets included in the daily updates.

now you run the scanner and it scans the files selected (whole computer, quick scan, or selected files) for any of the viruses in the database. if any are found it uses whatever method to quarantine or remove said virus.