Final answer:
A firewall uses stateful inspection to monitor connections and utilizes this information to identify and discard packets posing security threats. This dynamic security method adapts to traffic flow, providing stringent network protection.
Step-by-step explanation:
A firewall can use stateful inspection to monitor and record the status of each connection and can use this information in making decisions about what packets to discard as security threats. While performing this stateful inspection, the firewall keeps track of the state of active sessions and uses this knowledge to make more informed security decisions than those based only on static rules or packet contents. This method of security allows for a dynamic protection mechanism that can adapt to the flow of traffic over time, providing a robust defense against a wide array of network-based security threats.