What is difference between firewall and Anti Virus Software?

ANTIVIRUS

Antivirus software consists of computer programs that attempt to identify, thwart and eliminate computer viruses and other malicious software (malware).

Antivirus software typically uses two different techniques to accomplish this:

Examining (scanning) files to look for known viruses matching definitions in a virus dictionary

Identifying suspicious behavior from any computer program which might indicate infection. Such analysis may include data captures, port monitoring and other methods.

Most commercial antivirus software uses both of these approaches, with an emphasis on the virus dictionary approach.

Historically, the term antivirus has also been used for benign computer viruses that spread and combated malicious viruses. This was common on the Amiga computer platform.

FIREWALL

A firewall is an information technology (IT) security device which is configured to permit, deny or proxy data connections set and configured by the organization's security policy. Firewalls can either be hardware and/or software based.

A firewall's basic task is to control traffic between computer networks with different zones of trust. Typical examples are the Internet which is a zone with no trust and an internal network which is (and should be) a zone with high trust. The ultimate goal is to provide controlled interfaces between zones of differing trust levels through the enforcement of a security policy and connectivity model based on the least privilege principle and separation of duties.