Firewalls (in the software sense) first came to be in the late 80s, when the evolution of the internet indicated a need for an additional layer of defense for computers that are connected to it. At the time, firewalls were considerably expensive and not readily available to (or in demand by) the general population. By now you've probably heard of firewalls and already know that they are in place to protect your PC, but what exactly are they? What do they do?
A firewall is essentially a device or a set of devices that permit, deny, encrypt or proxy all of your computer's inbound and outbound traffic based upon your specific (or the default) settings. So what does that mean?
Basically, a firewall is in place to protect your computer or your network from any malicious or harmful activity. It's most popular application is in use with the internet. The internet is considered a non-trusted zone, due to the fact that the general public has access to it. If you do not have a firewall in place protecting your on-line computer, then essentially anyone with the know-how and the will to do so could potentially infiltrate your system and your personal data. For this reason, firewall settings for internet traffic are usually set fairly high, and outside sources can only access your computer with your expressed consent. For closed networks of computers, the trust level is usually higher, so it's not uncommon for firewalls to be set to permit file sharing (with varying degrees of permissions) between the computers on the network. A firewall serves an additional purpose when used on your network, as it can prevent machines infected with viruses from contaminating other machines on the network.
Having a firewall in place lets you decide exactly what information can be accessed from the internet or from other computers on your network. For instance, if you run your own server, you can have it set up so that internet users may view the web pages on your HTTP server, but they do not have access to send mail using your SMTP server (by doing so they would potentially be able to impersonate you).
No matter what your particular situation is or what business you conduct online, it is highly recommended to have your firewall set with the highest security standards. The only drawback to this is that it may impair the functionality of certain programs that depend on more open internet communication. In these instances, the program will usually alert you to let you know that they need specific firewall bypass privileges. You should be able to go into your firewall's settings and locate an option to grant special access to specific applications. Be sure to only grant this type of access to applications that you absolutely trust. Giving this type of access to programs that are unfamiliar to you or appear to be somewhat suspicious can leave your computer extremely vulnerable and its security may end up being compromised. Try to keep the number of applications with this access to a minimum.
Having a software firewall for your personal computer connected to the internet is a must. But what if you have several computers on your network? Instead of purchasing separate firewall applications for each machine, it may be more cost effective for you to purchase one hardware firewall to protect all of the computers on your network. If you'd like to increase your security a step further, you could use both methods in conjunction with each other to create an additional layer of security.
Many new PCs come equipped with perfectly effective firewalls already installed. However, if you are using an older machine or would simply like to upgrade to a firewall with more features, do your research online and find the one that best fits your needs. Several different types are available, with features ranging from the most basic to highly advanced and elaborate security features.
