What is the primary function of a network switch?

A network switch primarily functions to connect devices on a local network, allowing them to communicate with each other efficiently. It operates at the data link layer (Layer 2) of the OSI model and uses MAC addresses to forward data only to the intended device, which minimizes data collisions and optimizes network performance.

While the other options mention various networking functions, they do not align with the primary role of a network switch. For example, providing Wi-Fi access refers to the capabilities of a wireless access point, which enables devices to connect wirelessly to a network. Serving as a firewall relates to network security devices that monitor and control incoming and outgoing network traffic based on predetermined security rules. Lastly, monitoring network traffic pertains to network management tools or systems that analyze data flows for performance and security monitoring, which is not the fundamental role of a switch.

Thus, the primary function of connecting devices within a local network distinctly characterizes what a network switch does best.