What is difference between heuristic detection and sigbature scanning?

Answer 1

Heuristic detection looks for the characteristics of viruses and malware, while signature scanning looks for specific files known to be malware.

In other words, heuristic detection can find recently created malware on a system, because it "acts" like other malware.

Signature scanning looks at a list of known malware file names, and then sees if there are any of them on the computer.