Modems are devices that allow computers and other devices to connect to the internet by converting digital signals into analog signals and vice versa. A modem typically connects to a phone line, cable line, or fiber optic network to enable internet access. There are different types of modems, including DSL, cable, and fiber modems, each designed for specific types of internet connections. Some modems come integrated with routers, providing both internet connectivity and wireless networking capabilities. Shopping online for modems offers various options for home or business use, ensuring users can find the right modem for their internet service provider and connection type.