What is the function of a firewall in a networked system?

The function of a firewall in a networked system is primarily to secure the network from unauthorized access. Firewalls serve as a barrier between a trusted internal network and untrusted external networks (such as the Internet). They monitor and control incoming and outgoing network traffic based on predetermined security rules. By doing so, firewalls can block malicious traffic, protect sensitive data, and ensure that only authorized users and devices can access certain parts of the network.

In addition to blocking unauthorized access, firewalls can also log traffic for monitoring purposes, enforce policies regarding which protocols or applications can be used, and provide alerts for potential security breaches. This crucial role allows organizations to maintain their security posture and protect their data from various threats.

Other options might seem relevant, but they do not accurately reflect the primary function of a firewall. For instance, while increasing data transfer speed, facilitating better network routing, or providing data backup are important aspects of network management, they are not the primary functions of a firewall. The core purpose remains centered around security, making the correct choice clear.