A Layman's Guide to Firewall
Definition
A firewall by definition is a piece of software or hardware meant to protect your computer or network of computers from harmful activities of other computers/software etc. It is just like a guard sitting at the gate of your house keeping an eye on everyone coming in or going out. If any suspicious activity is observed, the firewall will prevent that to happen, most of the time by blocking the access to your computer.
How does a Firewall work?
It is with the advent of networks, both wired and wireless, that our computers have become increasingly unsecured. In order to keep the privacy of your data and at the same time provide the facility of accessing different resources spread throughout the internet we need such software-firewall. If you are not connected to a network you will not need a firewall. Therefore the most logical place to place your “guard” is at the gateway of data. Any data that is bound to enter your computer is first checked. It is checked for its origin-whether it was originated by a computer/software/website which does not pose a threat. Whether the data which could be in the form of scripts etc. is not meant to take away from or alter any important info in your computer.
Not only the data entering into your computer is checked but the data that is going out of your computer is also scanned for security. Why is this done? It is actually to prevent any malicious software that is already resident in your computer from stealing and sending away critical information.
What you can do with it?
Generally, a PC at your home does not need a firewall for protection unless you store sensitive or classified data in it-the data that you would not like to share with anyone. If you have a little home network then it is a good idea to protect your computers from any malicious software that might creep into the network. But if you have an office network then it is a must to deploy a strong firewall. It is a known fact that your competitors will be out there to sneak in to your network to steal your precious ideas or in other case just to destroy critical information to bring down the business. A firewall is such an important piece of software that Microsoft provides a firewall tool embedded into its operating systems. For details about how to configure firewall on your computer if you are using Windows XP click here.
Does it provide protection against viruses?
A firewall, as mentioned previously is meant to check the flow of critical information from your computer. Additionally, it checks whether any malicious software is entering your computer. Viruses on the other hand are not necessarily meant to steal critical information from your computer and transmit it to some remote computer. Viruses are meant to destroy the data that is present in your computer. So an antivirus is needed for protection against viruses. A firewall will not suffice.
Top Firewall Software Available
ZoneAlarm Firewall
Agnitum Outpost Firewall (Free)
Ashampoo Firewall (Free)
McAfee Firewall