What is Firewall?
A firewall is considered a first line of defense in protecting private information. Its 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 firewall is a system or group of systems that enforces an access-control policy between two networks. It may also be defined as a mechanism used to protect a trusted network from an untrusted network. The firewall can be thought of two mechanisms. One to block the traffic, and the other to permit traffic.
A firewall is a set of related programs, located at a network gateway server, that protects the resources of a private network from users from other networks. (The term also implies the security policy that is used with the programs.) An enterprise with an intranet that allows its workers access to the wider Internet installs a firewall to prevent outsiders from accessing its own private data resources and for controlling what outside resources its own users have access to!
The Firewall lets the safe Internet traffic pass while blocking the dangerous Internet traffic. It protects your computer against hackers and malicious Internet traffic such as worms and Trojan horses. The EastLink Internet Security Services “Firewall” includes the following components: firewall, application control, intrusion prevention and dial-up control.