What term describes devices or software that act as a checkpoint between the network and individual users?

• A. Firewalls
• B. Routers
• C. Switches
• D. Proxies

Answer: (A)

Firewalls are security devices or software placed at the boundary between a network and its users. They act as a checkpoint by inspecting and filtering traffic according to security rules, deciding what can enter or leave the network and thus protecting internal resources. Routers focus on moving data between networks and choosing paths, not enforcing per-user access policies. Switches connect devices within a network and don’t filter traffic at the edge. Proxies sit between clients and external resources and can filter or cache requests, but the defining boundary-check role described here is most accurately fulfilled by a firewall.