How antivirus works
Have you ever wondered how a traditional antivirus works? Here’s how :
Real-time scanning – your antivirus should include this option which checks every executable program you open against known types of malware. Antivirus also looks at different types of behavior in the program to see if there’s anything potentially malicious about it.
Full system scan – this is useful to check if any of the programs you already have installed is malicious or includes malware. Or you can use this scan to do a computer clean-up and rid your system of malware.
Virus definitions – these are the main way an antivirus solution identifies and stops malware. These definitions pertain to different types of known malware. If a program or file on your PC matches one of these definitions, your AV will quarantine it to stop it from spreading.
Credit : https://heimdalsecurity.com