Definition: A personal firewall can either be software or hardware that is installed upon or connected to a computer. A software implementation that protects the computer by filtering incoming messasges is installed on the computer’s hard drive. The hardware application involves a device with a MAC address that is located between the Internet and the computer. A hardware device, generally, has more built-in security features but would be a more expensive solution. The user, in each case, does have some capacity to customize.
Its Relevance: Any individual with a personal computer would be wise to have a customized software or hardware device between his or her machine and the Internet. It can block, by filtering, unwanted packets from the Internet and even block known malicious software, depending upon the sophistication of the technique used.