Final answer:
The technique called stateful inspection is used to stop data packets originating outside the organization, inspect them, and pass approved packets through a firewall.
Step-by-step explanation:
The technique that stops data packets originating outside the organization, inspects them, and allows them to pass through the firewall is called stateful inspection. Stateful inspection tracks the state of active connections and makes decisions based on the context of the traffic, rather than just inspecting individual packets in isolation. Through this method, it ensures that incoming packets are part of a known active connection.
Packet filtering, in comparison, looks at individual packets in a more superficial manner without keeping track of connection states. Application proxy filtering serves as an intermediary; it inspects the data at the application layer, making security decisions based on specific application rules. Deep packet inspection examines the data within packet headers and payload for even greater scrutiny. NAT (Network Address Translation) primarily translates private IP addresses to public ones for outbound packets, which provides an added layer of security but is not focused on in-depth packet inspection itself.