What is the role of a firewall?

• A. Blocks unauthorized access while permitting outward communication
• B. Encrypts all data on the network
• C. Routes packets between networks
• D. Stores user credentials

Answer: (A)

A firewall acts as a barrier between networks, enforcing security rules to control traffic. Its main job is to block unauthorized access while allowing legitimate outbound and necessary inbound communication. By inspecting packets based on rules such as IP addresses, ports, and protocols, it prevents attackers or malware from directly reaching internal systems while still permitting trusted traffic to pass. This selective filtering is what keeps a network protected without hindering normal Internet use.

Encryption, routing, and credential storage are handled by other components: encryption protects data in transit or at rest, routing moves packets between networks, and credentials are stored by authentication systems.