antivirus,personal firewalls and maintenance utilities

Antivirus is such very important to the computer because it cleans up the virus that destroys documents.Antivirus software is now designed to combat a wide range of threats, including worms, phishing attacks, rootkits, Trojans, often described collectively as malware.The examples of the antivirus programs are the NORTON Antivirus, NOD32 antivirus and many more.
A personal firewall is an application which controls network traffic to and from a computer, permitting or denying communications based on a security policy.This firewall will be the one to accept such communications or denied it depending if its acceptable by the security policy.Example of the personal firewall is the tiny personal firewall.
Maintenance utilities is the one who will maintain the good working of the computer.