What is the primary function of a router in a network?

The primary function of a router in a network is to connect multiple networks and direct traffic between them. Routers facilitate communication between different devices and networks by determining the best path for data packets to travel. This involves analyzing the destination address of each packet and using routing tables and protocols to forward the packets across networks toward their intended destinations.

In contrast, the other functions described in the other choices do not accurately represent the role of a router. Serving web pages pertains to web servers, storing data is a function of storage devices, and converting digital signals to analog is related to modems. Thus, it's clear that the main task of a router focuses on network connectivity and traffic management.