A firewall is a barrier that filters the traffic coming into and going out of your network. It follows a set of rules to decide which traffic is allowed through and which is blocked, and it controls who can reach what on your systems.
Think of a firewall as the gatekeeper for your network. It is essential, but it is not enough on its own. Modern threats arrive through email, malicious links, and other channels that a firewall does not catch, so security needs to be layered. A firewall is one important layer, not the whole answer.
