Norton AntiVirus (NAV) is an antivirus developed by Symantec Corporation, with a focus on providing malware and exploit protection. It is available for both Microsoft Windows and Mac OS X. It was made on September 12, 2006. It sometimes is installed on first use computers, like McAfee.
Norton always monitors your computer when turned on. It advises your browsing, making your browsing safer, it can find files inside the programs you install. It knows if a program you installed is a trojan, being a very useful tool when avoiding viruses, worms and such.