What is a Firewall?

If you are a basic Internet user or an advanced Internet user then it is likely that you have at least heard the term "firewall" before. Home Internet users and even corporate Internet users alike know at least that firewalls are a form of security. This is exactly what a firewall is; it protects your computer from objective or compromising Web sites and from potential hackers.

Imagine a firewall as an electrical fence that you have put around your home to protect yourself from outside sources of harm and from those with ill intent. That is what a firewall does; it acts as a barrier to keep harmful forces away from your computer.

Firewalls are programs that filter information that comes through your Internet connection to your computer. If something is trying to get in and it is flagged by the filters it will not be allowed to enter your computer system. 

If there is no firewall on your computer then information of any type is free to flow from the Internet right into your computer system. If you are protected by a firewall it acts as a filter and bounces back the things that could harm your computer or compromise it in any way. Think about how valuable a firewall could be to businesses and larger corporations.

The more computers that a company has networked together the more damage can be done. Without a firewall every single computer is vulnerable to anyone on the Internet and Internet hackers will have a field day.

When companies utilize firewalls it gives them a great degree of control over what their employees do on the Internet and how they use the network. It also gives employers control in other areas such as which Web sites that their employees can connect to and if any files are allowed to leave the company via the Internet.

There are three usual methods that firewalls use to control the flow of traffic on the network. Small chunks of data, referred to sometimes as packets, are ran through a set of filters. Those that make it through are sent to the system that is requesting them and all others are thrown away. This is called packet filtering.

Proxy service is another way of how firewalls control the flow of traffic on the Internet. Once the information from the Internet is received by the firewall, it would then be forwarded to the requesting system.

There is a newer system that does not look over the contents of each package quite as intricately but rather compares parts to other databases that are reputable. If the match is even reasonable then it is allowed to pass through, if not it is denied.

If you combine a firewall along with a good anti virus program then you stand a good chance of having full protection. There are some levels of spam that are just avoidable unless you completely stop receiving emails.

There are levels for which you can determine your security starting with blocking everything would equip you with the ultimate level of security but that would be redundant of even having Internet.

Experts recommend that you begin by blocking everything and then go back and selectively decide which traffic you are going to allow back in. Many who are unfamiliar with this should likely just use the default settings unless you discover a reason to change it later.