If you have been using Internet on a regular basis or working in a large company and surf the Internet while you are at work, you must have surely come across the term firewall. You might have also heard of people saying “firewalls protect their computer from web attacks and hackers” or “a certain website has been blocked by firewall in their work place”. If you have ever wondered to know what exactly is this firewall and how it works, here we go. In this post I will try to explain “How firewalls work” in a layman’s terms.

How Firewalls Work

 

Firewalls are basically a barrier between your computer (or a network) and the Internet (outside world). A firewall can be simply compared to a security guard who stands at the entrance of your house and filters the visitors coming to your place. He may allow some visitors to enter while denying others whom he suspects of being intruders. Similarly a firewall is a software program or a hardware device that filters the information (packets) coming through the Internet to your personal computer or a computer network.