What is the function of a firewall?

The primary function of a firewall is to monitor and control incoming and outgoing network traffic. It acts as a security barrier between a trusted internal network and untrusted external networks, such as the internet. Firewalls enforce security policies by allowing or blocking data packets based on predetermined rules, helping to protect the network from unauthorized access, attacks, and other security threats. This capability is essential for safeguarding sensitive information and ensuring the integrity of network communications. Effective use of a firewall can prevent malicious traffic while allowing legitimate traffic to pass, creating a controlled environment for data exchange.

The other choices, while related to security and data management, do not accurately describe the primary function of a firewall. Scanning for viruses pertains more to antivirus software, encrypting data relates to protecting data confidentiality, and enhancing network speed is not a direct function of a firewall but rather a characteristic of network infrastructure and optimization techniques.