Because they already segregated networks, routers could apply filtering to packets crossing them. The predecessors to firewalls for network security were routers used in the late 1980s. The term was applied in the late 1980s to network technology that emerged when the Internet was fairly new in terms of its global use and connectivity. Later uses refer to similar structures, such as the metal sheet separating the engine compartment of a vehicle or aircraft from the passenger compartment. The term firewall originally referred to a wall intended to confine a fire within a line of adjacent buildings. A firewall typically establishes a barrier between a trusted network and an untrusted network, such as the Internet. In computing, a firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

Security information and event management (SIEM).

Host-based intrusion detection system (HIDS).In those cases, you should ask your network administrator for guidance on whether you need a firewall on your computer. In some cases, network administrators may configure all computers on the network so that you cannot turn on the firewall while your computer is connected to the network. If your computer is part of a business, school, or other organizational network, you should follow the policy established by the network administrator.You should have a hardware firewall (such as a router) to protect your network, but you should also use a software firewall on each computer to help prevent the spread of a virus in your network if one of the computers becomes infected.

If you have more than one computer connected in the home, or if you have a small-office network, it is important to protect every computer.If you use a computer at home, the most effective and important first step you can take to help protect your computer is to turn on a firewall. NOTE: A firewall is essential, but you also need antivirus software and antispyware software.

A firewall is a software program or piece of hardware that helps screen out hackers, viruses, and worms that try to reach your computer over the Internet.

What is firewall in computer