A firewall that prioritizes traffic based on the quality of service (QoS) settings, ensuring that critical services receive the bandwidth they need.

A firewall that filters traffic based solely on predetermined static rules, without the capability to remember previous connections or sessions.

A firewall that maintains a table tracking the state of all active connections and allows or denies traffic based on the context of its communication.

A firewall that inspects the data payload of packets to identify and filter out malicious content, such as viruses or malware.