Definition - What does Internal Modem mean?
An internal modem is a network device that is contained on an expansion board that plugs into the motherboard. Unlike an external modem, an internal modem contains no lights to inform the user of its current function or changing modem states. Instead, the user must rely on the software that came with the modem.
Internal modems are also known as on-board modems.
Techopedia explains Internal Modem
Internal modems come in two types: dial-up and wireless. Dial-up modems require a connection with a telephone line, network access phone number and username and login ID.