Which term refers to computer hardware and software that block unauthorized communications between an institution's network and external networks?

• A. Firewall
• B. Encryption
• C. EDI
• D. EPR

Answer: (A)

A firewall is the mechanism that blocks unauthorized communications between an institution’s internal network and external networks. It acts as a security gate, enforcing a defined policy about what traffic is allowed to enter or leave. Firewalls can be hardware, software, or a combination, and they protect the network by inspecting traffic—whether at the network, transport, or application layer—and blocking anything that doesn’t meet the rules. They may also provide features like NAT and VPN support to manage connections securely.

Encryption, while essential for keeping data confidential, does not by itself prevent unauthorized network access or control traffic flow; it protects data in transit or at rest after access has already been granted. EDI (electronic data interchange) is a method for exchanging business documents and doesn’t filter network traffic. EPR (electronic patient record or related systems) concerns storing or managing records and is not a device or software that governs network access.