What is a Firewall

A firewall is a type of hardware or software. the main purpose of the firewall is to hide your computer with in the network. So that what the program want to access go throught that and if any unknown connection attempt to start it blocks it. It is also responsible to prevent any unauthorised attack from outside

Hi friend.. A firewall is a secure and trusted machine that sits between a private network and a public network.The firewall machine is configured with a set of rules that determine which network traffic will be allowed to pass and which will be blocked or refused. Firewall can be constructed in quite a variety of ways.

From Wikipedia: [i]A firewall is a part of a computer system or network that is designed to block unauthorized access while permitting authorized communications. It is a device or set of devices configured to permit, deny, encrypt, decrypt, or proxy all (in and out) computer traffic between different security domains based upon a set of rules and other criteria. Firewalls can be implemented in either hardware or 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. There are several types of firewall techniques: Packet filter: Looks at each packet entering or leaving the network and accepts or rejects it based on user-defined rules. Packet filtering is fairly effective and transparent to users, but it is difficult to configure. In addition, it is susceptible to IP spoofing. Application gateway: Applies security mechanisms to specific applications, such as FTP and Telnet servers. This is very effective, but can impose a performance degradation. Circuit-level gateway: Applies security mechanisms when a TCP or UDP connection is established. Once the connection has been made, packets can flow between the hosts without further checking. Proxy server: Intercepts all messages entering and leaving the network. The proxy server effectively hides the true network addresses.[/i] Hope this helps..

Firewalls are softwares that prevent inauthorized access to the computer from the internet. They are often confused with anti-virus programs but unlike anti-virus they prevent any hacker or program from the internet from entering the system and making changes. They monitor the Ports(thin optical wires in router cable that allows connecting the internet) and make sure any unauthorised program doesnt enter the computer. They also notify when user make changes to system such as installing/uninstalling a software. Examples include windows firewall, comodo firewall etc

Firewall blocks hackers from entering into your computer system, it blocks your ip address from people who are trying to get it, either by trojaning,telneting etc. its good to have :)

Firewall is a software that restricts the incoming and outgoing connections in your computer. Only applications you certify are eligible to make connection and accept connection. This is to protect your computer from hackers. You should update your firewall software often because firewall are also being hacked by hackers.

The comment above me is right firewall like antivirus helps protect our PC's from intruders and hackers so use one with a good antivirus/antispyware your PC will be safe.