Hi, they are special program that protects your PC from being violated. Generally speaking, antivirus software plays an important role in protecting PC. Antivirus software is designed for eliminating virus, Trojan and malware. It can monitor, scan and upgrade automatically. As you know, Kaspersky, Norton and Panda are all famous antivirus software.
They are programs that specifically look through your computer to find, stop and destroy programs that are malicious to your computer.