What role does a firewall play in network security?

A firewall plays a crucial role in network security by monitoring and controlling network traffic. Its primary function is to serve as a barrier between a trusted internal network and untrusted external networks, such as the internet. By applying a set of predefined security rules, the firewall examines incoming and outgoing data packets. This helps prevent unauthorized access to or from the network.

In this capacity, firewalls can block harmful traffic while allowing legitimate traffic to pass through, thus protecting sensitive data and resources from potential threats. This capability is essential for defending against various types of attacks, such as unauthorized access attempts, denial of service (DoS) attacks, and other malicious activities. Firewalls act as the first line of defense in a comprehensive network security strategy, ensuring that only approved connections are established.

Other options, while relevant to cybersecurity, do not accurately define the primary role of a firewall. Speeding up internet connections, providing antivirus protection, and storing user credentials are not functions performed by a firewall, which is specifically designed for traffic filtering and security enforcement.