Brianna

Firewall is a security software that allows administrators to control access to network resources and protect computer systems from unauthorized access. Firewall software can be implemented on a local area network, a wide area network, or on an intranet.

A firewall can be classified according to its function:

1. Network perimeter firewall: Protects the network perimeter by controlling the incoming and outgoing traffic.

2. Intrusion prevention firewall: Monitors network activity for signs of unauthorized activity, such as attempts to exploit security vulnerabilities.

3. Application firewall: Controls the traffic that passes through an application.

4. URL filtering firewall: Filters web traffic by identifying specific Uniform Resource Locators (URLs).

5. Stateful packet inspection firewall: Enables administrators to track and monitor the traffic flowing through the network.

A firewall can be implemented on a variety of platforms, including Windows, UNIX, and Linux. Examples of firewall applications include the Windows firewall, the Linux iptables firewall, and the UNIX firewall.