Which piece of hardware is necessary for connecting a computer to the Internet?

The modem is a crucial piece of hardware for connecting a computer to the Internet because it modulates and demodulates the signals that travel between your computer and the Internet service provider (ISP). Essentially, the modem translates digital data from your computer into analog signals for transmission over traditional phone lines or cable systems, and vice versa for incoming data. This process allows the computer to communicate with the broader Internet infrastructure.

In a home network setup, while routers, switches, and servers play important roles, they cannot independently establish a connection to the Internet. A router, for example, is used to route data between devices on a local network and manage the traffic to and from the modem. A switch connects devices within a local area network (LAN) to enable communication among them but does not connect to the Internet itself. A server provides services and resources to other computers on the network, but it requires an Internet connection through a modem or router to interact with external networks. Thus, the modem is essential for achieving that initial connection to the Internet.