Find the definition of the most commonly used cyber security terms in our glossary below.

What is Firewall in cyber security?

A firewall functions as a shield between a trusted internal network and less trusted external networks, such as the internet. Whether it's a standalone system or embedded in a router, a firewall inspects and regulates all incoming and outgoing network traffic. It works based on predetermined security policies — blocking packets failing to meet these criteria while permitting others, thus securing networks from potentially harmful information. The firewall also logs network activities and can provide alerts for suspicious activities. There are different types of firewalls, including network firewalls, proxy firewalls, application-level gateways, circuit-level gateways, and packet filters. With cyber threats becoming more sophisticated, firewalls, as the first line of defense, have also advanced. Modern firewalls, like NGFW (Next-Generation Firewalls), add additional features like intrusion prevention, encrypted traffic inspection, and bringing application-level inspection to the playground.