Firewall (computing)

A firewall is like a wall that stands between your computer and the Internet. In the same way that a real wall will keep people and animals out of a house, a firewall helps to protect your computer from viruses, malware, and other computer threats. Anytime something tries to get into your computer, the firewall checks to make sure it should be allowed in. If the firewall thinks the item is ok, it lets it in and the item can use your computer; but if it is not ok, the firewall will block it and prevent it from entering.