Thread: What's a firewall?

A firewall is software that sits between your local network and the internet inspecting the data traffic passing between the two to protect local users from hackers, trojans and other common threats. At its most basic a firewall will be configured to block all unsolicited inbound traffic, but that really doesn't provide much protection. In addition, therefore, most firewalls can scan for tell-tale signs of common attacks and block them when detected. More sophisticated firewalls can be further programmed to block specific protocols, shut down unused ports, prevent access to blacklisted websites " and so on.

Virtually all modern internet routers have a firewall of some kind built in. However, most are pretty basic and may not be fully activated by default, so it's worth checking what you've got and whether it's turned on. Bear in mind too that this kind of firewall will only protect PCs while they are attached to the Lan. If you take a notebook out and about and connect to other networks, a software desktop firewall such as the one provided in Windows will be required, as will anti-virus and other standard security software.