Ask most people what the latest version of McAfee or Norton installed on their home computer actually does, and they'll likely tell you it protects them from computer viruses. While that's true, it's a little too simple of an answer. Today's best antivirus software has many features designed to protect users from a variety of online threats -viruses, spyware, Trojans, and worms, for instance – and optimize computer performance. Here are the most common ones:
Scans of incoming files: Trying to open a file someone sent you? Visiting a Web site that contains a hidden virus? Many antivirus programs will stop these files from entering your system. Often, you'll get a notification that a Trojan is trying to enter your system. When it's detected at this stage, it can easily be blocked.
Scans of the computer: Sometimes viruses and other malware get missed by screening tools, no matter how careful you are. You can perform a system scan using most antivirus software. At the end, you'll be informed of any potential threats that were found and how these threats were resolved.
Tools to clean up computers: Probably the most common complaint among users is that computers seem to slow down after a while. This can be due to a variety of things, and antivirus software often has features to clean up computers and make them run faster.
Tools to prevent spam: Your antivirus software probably has a feature designed to help you cut down on the amount of spam you receive. You just have to "train" the system how to recognize spam messages, a small time investment that is well worth it in the long run. Just imagine if you could stop most of those junk e-mails from ever getting to your inbox in the first place.