This image illustrates the interconnected networks that make up the Internet. It begins with a Mobile Network: a cell phone tower surrounded by a car receiving Internet through its antenna, a stoplight, multiple smartphones, and a laptop. The cell phone tower connects to a router; this router connects to a National or Global ISP, illustrated by a group of routers. This network connects to a Local or Regional ISP, represented by a group of routers. These routers send signals through telephone lines to a Home Network and an Enterprise Network. The Home Network includes a router and a base station sending signals to a laptop computer, a refrigerator, a thermostat, a desktop computer and a wireless keyboard. The Enterprise Network includes several routers and link-layer switches sending signals to desktop computers and servers, and a base station sending wireless signals to laptops and a tablet device. Below this is the key, identifying the various devices included above.