virus= harmful
malware =annoying
A virus may destroy/encrypt important files, crash your computer, block updates and programs, steal personal data such as banking, etc.
Malware on the other hand, may hijack your browser, show pop ups or fake alerts.
most antivirus only detect viruses, thats why we need a different app for malware.
back in the day malware wasnt a thing, not everyone was online so antiviruses only detected viruses