What does a Firewall do?

Novice Users Explanation

So what does a firewall actually do? Quite simply put, a Firewall protects your computer from intrusion (scanning or attack) by hackers or script kiddies while it is connected to the Internet. a firewall examines electronic data coming in to, or out of, a computer (or network) and compares it to rules it has been given. If that data matches the rules which say it is OK, it will let the data pass. If it doesn't, it blocks the data. We could give you more details but that is when it gets confusing. Just think of a Firewall as a piece of software (or hardware for those with more computers) that keeps the bad guys out and let's the good ones in.

Advanced Users Explanation

There are many people who still use the internet without thinking twice about protecting themselves when online. Most of these people are home or small business users who never give it a second thought, or just don't understand enough about the risks to worry. Using the internet without a firewall can be explained quite easily - You wouldn't leave your house or office unlocked, or with the windows and doors wide open so that anyone can walk in and look around, or even steal your items, but using the internet isn't much different than that. If you are online without a firewall you are leaving it wide open to attack, and intruders and thieves could view or steal your information.

What a Firewall does NOT do?

Don't think a Firewall will give you full security and make you completely safe online, that just isn't true. Yes it is one of the first lines of defence, but on it's own it will not protect you 100%.

The main thing a firewall does it protect you from prying eyes. It stops thieves and intruders from accessing your computer, laptop, workstation or server. A good firewall can also protect you from malicious Worms. A firewall also prevents confidential information on your system from being sent without your permission. This could be your passwords, bank details and other personal information.

Have you heard of identity theft? Internet hackers know thousands of ways to break into vulnerable PC systems. In seconds, they can steal private files, credit card information, tax records, passwords and Social Security Numbers. Remote thieves can even hijack your system to send spam messages, or plant destructive viruses.

You will also need to use other protective steps outlined in on this site. Some of the things that a Firewall will NOT DO are:

Types of Firewall.

A Personal Firewall (also known as a desktop firewall, or Software firewall) is installed on each computer that is connected to the internet and monitors (and blocks, where necessary) internet traffic. It is used to help protect a single Internet-connected computer from intruders. Personal firewall protection is useful for users with "always-on" connections such as DSL, cable modem or dial-up connections.

Microsoft Windows XP (with Service Pack 2) has a basic Personal Firewall. We recommend you replace it with a more sophisticated commercial desktop firewall or supplement it with a hardware firewall. The reason for this is that you have more control over it and it has added benefits and features.

Hardware firewall

Hardware firewall's can be purchased as a stand-alone product but more recently hardware firewall's are typically found in broadband routers, and should be considered an important part of your system and network set-up, especially for anyone on a broadband connection. Hardware firewall's can be effective with little or no configuration, and they can protect every machine on a local network. Most hardware firewall's will have a minimum of four network ports to connect other computers, but for larger networks, business networking firewall solutions are available.

Which Firewall should i use?

The differences between a software and hardware firewall are vast, and the best protection for your computer and network is to use both, as each offers different but much-needed security features and benefits. Updating your firewall and your operating system is essential to maintaining optimal protection, as is testing your firewall to ensure it is connected and working correctly.