The word Firewall takes its name from the world of architecture, where it means a partition made of fireproof material. In the world of computers and networking, a firewall also helps to stop you getting burned, by keeping outsiders breaking into your website, and metaphorically burning it to the ground.
It’s one of the key technologies that keep your computer or network safe from hackers and malicious software. Firewall software can control the traffic moving between networks and protect home and office networks from all the destructive stuff that’s always circulating on the Internet.
For internal networks, which often connect to the Internet through routers, the router itself provides a hardware solution with some basic Firewall functions. Any computers that connect to a router will also have their own Firewall software—or should do. Windows PCs often comes with freeware or trial Firewall software to get you started, and Windows itself has a built-in firewall application if all else fails.
Firewalls aren’t quite like brick walls. They’re more like intelligent gatekeepers. They have enough flexibility built in to them to either block or allow certain programs from accessing the Internet, specific traffic, sites, or IP addresses. You can even tell them to block certain protocols and ports. Some Firewall software can weed out specific types of media, as well as excluding certain words or phrases or stopping content downloading and uploading. This kind of flexibility means that you can easily set different levels of security for all the computers on your network.