What is Firewall?

[michejohnson]

A firewall protects networked computers from intentional hostile intrusion that could compromise confidentiality or result in data corruption or denial of service. It may be a hardware device (see Figure 1) or a software program (see Figure 2) running on a secure host computer. In either case, it must have at least two network interfaces, one for the network it is intended to protect, and one for the network it is exposed to.

Hardware Firewall


Computer with a Firewall


A firewall sits at the junction point or gateway between the two networks, usually a private network and a public network such as the Internet. The earliest firewalls were simply routers. The term firewall comes from the fact that by segmenting a network into different physical subnetworks, they limited the damage that could spread from one subnet to another just like firedoors or firewalls. Figure 1: Hardware Firewall
Hardware firewall providing protection to a Local Network

[jacobhenriques]

A firewall is a fire-resistance rated wall assembly intended to slow the spread of fire from one side to the other, and are certification listed. Firewalls subdivide a building into separate fire areas, and are located in accordance with the locally applicable building code.

[WalterArcher]

Firewall technology is a barrier designed to prevent unauthorized or unwanted communications between computer networks or hosts.It is a device or set of devices configured to allow or deny applications based on a set of rules and other criteria.Firewalls can be implemented in hardware or software or a combination of both.

[filisili50]

Recently I just reading this forum at that time I just found this article. One of the best software which implemented in hardware or software or a combination of both. Here very good guide and easy way to understand what is firewall.

[jhonkevin]

Firewalls can be implemented in both hardware and software, or it is a combination of both. Firewalls are frequently used to prevent unauthorised Internet users from accessing private networks connected to the Internet.a firewall, working closely with a router program, examines each network packet to determine whether to forward source to toward its destination. Firewalls are also work as Proxy server.

[rosesteven23]

Firewall is a part of your computer system which will block the unauthorized access to your system.
I like this post very much. You have given nice information about Firewall.
I am sure people will like this information and also very useful them.

[christaker]

A firewall is considered a first line of defense in protecting private information. For greater security, data can be encrypted. Computer security borrows this term from firefighting, where it originated. In firefighting, a firewall is a barrier established to prevent the spread of fire.

[jimmy choo]

From the firewall, initialize and mount the additional file - system you specify for each system.
A firewall is a system or group of systems that enforces an access control policy between two networks.

[solvalavan12]

Firewall is very important to the protect your computer system and your personal information as well. Firewall works with two ways. Generally, data that comes in is analyzed by the firewall to determine the IP address it is coming from and the content that it contains.This system then checks to see if this information is compliant with rules that you are able to configure.

[shure microphones]

Firewall is a device to help ensure information security, will follow the specific rules that allow or restrict transmission of data through. Firewalls can be a dedicated hardware can also be mounted on a set of general hardware software.