An application firewall is a type of firewall that governs traffic to, from, or by an application or service.

Application firewalls, or application layer firewalls, use a series of configured policies to determine whether to block or allow communications to or from an app.

Traditional firewalls control data flow to and from the CPU, examining each packet as it passes through. An application firewall takes it further by controlling the execution of files or code by specific applications. This way, even if an intruder gains entry to a network or server, they can’t execute malicious code.