A system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially Intranets. All messages entering or leaving the Intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.
A combination of hardware and software that separates a LAN into two or more parts for security purposes. The fire wall is built between the main computer system and the network in order to retain internal network security and prevent disruption, or malicious attack.
A protection against computer invasion through a combination of hardware and software.