What is a firewall and how does it help security?

• A. A firewall monitors and filters network traffic based on rules to block unauthorized access.
• B. A firewall manages user passwords.
• C. A firewall speeds up video playback.
• D. A firewall stores backup copies securely.

Answer: (A)

Firewalls monitor and filter network traffic to block unauthorized access. They act as a barrier between trusted networks and the outside world, using rules to decide which data flows are allowed and which are blocked. By permitting only legitimate connections and blocking the rest, they reduce the risk that attackers can reach devices, steal information, or spread malware. Firewalls can be hardware devices, software programs, or cloud services, and they typically control traffic by source or destination IPs, ports, or protocols, sometimes performing deeper checks on applications. They also log activity to help you spot suspicious behavior. Remember, a firewall is one part of security—good configuration and complementary tools and practices are needed for stronger protection.