An Antivirus is offered by many different software development companies, following are some fundamental functions which an antivirus must perform
-Scan all or selected files or directories in a system for any malware or known virus.
-Block viruses, spyware, Adwares, ransomware & other malware
-Allow the user to schedule scans and also to automatically run as per the need
-Block unsafe web-links, download files, and attachments in email
-Allow the user to start a scan of a specific type of a USB, Hard disk and a storage device of any type
-Remove any code detected which is malicious in nature and has been installed on the system without the user’s consent
–Notify the user about any infection and ask the user to clean the file.