The device that divides and connects two networks is a ___.

The device that effectively divides and connects two networks is a router. A router serves as a gateway for data packets, determining the best path for data to travel between different networks. By analyzing the destination IP addresses in the data packets, the router can direct the packets from one network to another, allowing communication between devices that are located on separate networks.

In contrast, a switch operates within a single network and directs data between devices on that same network by using MAC addresses. A hub, which is a more basic networking device, simply transmits data packets to all connected devices without filtering. A modem, on the other hand, modulates and demodulates signals for communication over telephone lines or cable systems, facilitating internet access rather than connecting separate networks. Thus, the primary function of a router aligns it specifically with connecting and dividing networks, making it the appropriate choice for this question.