You've heard that you need a firewall, but there are so many options. Software firewall? Hardware firewall? How do you know which is right for you?

First of all, hardware is something you can see, like the monitor you are looking at to read this text right now. Hardware refers to the hard physical elements—the computer, the keyboard, the circuitry inside your computer—anything you can see and touch. Hardware always includes some form of software. For example, your computer keyboard has a software program written into the circuitry that allows what you type to appear on the screen. But you don't have to purchase this software for your keyboard. It's already there.

Software, on the other hand, is a computer program that tells the hardware exactly what to do. This webpage, for example, was written in a computer language called HTML. HTML tells your monitor how to display the text you are reading now. Software is the name for the instructions that tell the computer what to do.

A hardware firewall is a small metal box filled with plug openings, or ports. You hook your computer network into the box then set it up on your computer, just as you would a new printer or other peripheral. Because it's not physically on your machine, a hardware firewall is less vulnerable than a software firewall.

Software firewalls give you the level of protection you need to keep safe from hackers and other unwanted intrusions because software is far easier for computer novices to customize. The features are suited to smaller home networks.

Some top software firewall packages also include antispam, antivirus, even anti-popup ad software. Some software firewalls include parental controls to manage what kinds of websites your children visit. Some packages allow you to block photos and specific text content that you do not want your children to view.

Hardware firewalls are best suited to businesses and large networks. IT professionals often have hardware firewalls in their homes. But for average consumers, software firewalls are best suited for home use.

To learn more, check out our list of the best personal firewalls available.