Most antivirus programs operate in two primary modes:
- They’re used to “scan” your entire computer (or a part of it) for viruses that may already be present there.
- They’re used to actively monitor your computer’s activities — in particular, that part of Windows that controls the creating, opening, and closing of computer files — so the antivirus program can examine each active file for signs of a virus.
The latter function is automatic, and it has a variety of names. Symantec calls it Auto-Protect , while McAfee uses the term ActiveShield. But whatever the name, the function is the same: Your antivirus program is actively preventing a file with a virus from being implanted in your computer in the first place. This is a Very Good Thing.