What is the function of a firewall?

A firewall serves the critical function of protecting a network from unauthorized access and attacks. It acts as a security barrier between a trusted internal network and untrusted external networks, such as the internet. By examining data packets entering or leaving the network, a firewall can determine whether to allow or block specific traffic based on predetermined security rules. This functionality is vital in safeguarding sensitive information and maintaining the integrity of the network from potential threats, such as hackers and malware.

While firewalls do play a role in managing some aspects of network traffic, their primary purpose is focused on security. Enhancing network speed or allowing remote access to a network are not core functions of a firewall; instead, they are outcomes of other networking components and technologies.