02-09-2017, 10:27 AM
In computing, a firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. A firewall typically establishes a barrier between a secure and secure internal network and another external network, such as the Internet, which is not supposed to be secure or trusted.
Firewalls are often categorized as network firewalls or host-based firewalls. Network firewalls filter traffic between two or more networks; are software devices that run on general-purpose hardware or hardware-based firewall computer devices. Host-based firewalls provide a layer of software on a host that controls network traffic on and off that single machine. Firewall appliances can also offer other functionality to the internal network they protect, such as acting as a DHCP or VPN server for that network.
The term firewall was originally referring to a wall intended to confine a potential fire or fire within a building. More recent 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 was applied in the late 1980s to the networking technology that emerged when the Internet was fairly new in terms of its global usage and connectivity. The predecessors of firewalls for network security were the routers used in the late 1980s.
Firewalls are often categorized as network firewalls or host-based firewalls. Network firewalls filter traffic between two or more networks; are software devices that run on general-purpose hardware or hardware-based firewall computer devices. Host-based firewalls provide a layer of software on a host that controls network traffic on and off that single machine. Firewall appliances can also offer other functionality to the internal network they protect, such as acting as a DHCP or VPN server for that network.
The term firewall was originally referring to a wall intended to confine a potential fire or fire within a building. More recent 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 was applied in the late 1980s to the networking technology that emerged when the Internet was fairly new in terms of its global usage and connectivity. The predecessors of firewalls for network security were the routers used in the late 1980s.