What is a firewall and what does it do? What's its purpose?

Question

What is a firewall and what does it do? What's its purpose?

Answer 1

think of the firewall on a car. it sits between you and the motor to prevent fire or heat from getting to you. A firewall on a computer is there to keep hackers and certain other applications from getting into your computer.

Answer 2

A firewall (software/hardware) is like a bouncer standing at the entrace of a night club. His job is to ensure the safety and integrity of his customer's by denying entry to trouble makers.

Occasionally, the odd trouble maker will gain entry into the night club, (lets say he is trying to pilfer a jug and a couple of ashtray's, but replace the jug for your credit card details and the ashtray with your porno stash) the bouncer's job is to make sure he doesn't make it past the door with your goods.

A good bouncer (firewall) will halt the bad guy/s in his tracks allowing enough time for the good guy's, (antivirus/spyware programs) to come in and haul his sorry as5 off to jail (virus/spyware/vault).

Set up properly, a firewall should stop the majority of the scoungrels snooping around inside your computer but if somehow your computer has been compromised it should stop the majority of these snoopers from sending back your credit card details or what other information they have gathered.

No firewall can gaurantee you 100% protection, a determined cracker with the right knowledge will gain entry, but it will stop the script bunnies or wannabe crackers.

Sorry about my sucky analogy but I hope it helps.

Answer 3

A firewall is a dedicated appliance, or software running on another computer, which inspects network traffic passing through it, and denies or permits passage based on a set of rules.

Firewall
From Wikipedia, the free encyclopedia
http://en.wikipedia.org/wiki/Firewall

A firewall's basic task is to regulate some of the the flow of traffic between computer networks of different trust levels. Typical examples are the Internet which is a zone with no trust and an internal network which is a zone of higher trust. A zone with an intermediate trust level, situated between the Internet and a trusted internal network, is often referred to as a "perimeter network" or Demilitarized zone (DMZ).

A firewall's function within a network is similar to firewalls with fire door in building construction. In former case, it is used to prevent network intrusion to the private network. In latter case, it is intended to contain and delay structural fire from spreading to adjacent structures.

A good free firewall is Comodo Firewall Pro http://www.personalfirewall.comodo.com/
"It's Free. Forever. No Catch. No Kidding"

Answer 4

a firewall is a thing that blocks viruses

Answer 5

this site should explain it pretty well
http://www.howstuffworks.com/firewall.htm
page 1
page 4

get ZoneAlarm it is highly ranked, free, and trustworthy.

http://www.download.com/3150-10435_4-0-1-6.html?qt=&rows=10&start=0&operatingSystemId=&licenseTypeId=49&fileSize=&ca=