What is a Firewall?
Just as a firewall in a building attempts to prevent a fire from spreading, a computer firewall attempts to prevent malicious or unwanted software from spreading to your computer from the network.
A Firewall also helps to prevent unauthorized users from accessing your computer.
In a default Linux installation, a firewall exists between your computer or network and any untrusted networks, for example the Internet. It determines which services on your computer remote users can access. A properly configured firewall can greatly increase the security of your system.
It is strongly recommended that you configure a firewall for any system with an Internet connection properly, to secure your computer from malicious software and external attackers.
In our next post we would like to throw some light on the ways to configure a firewall on various popular flavours of Linux.