Any device that is a source of data transmission over a serial telecommunications link. Typically, data terminal equipment (DTE) can be a computer, a terminal, a router, an access server, or some similar device. The earliest form of DTE was the teletype machine.
Graphic D-9. Data terminal equipment (DTE).
The term «DTE» specifically refers to a device that uses serial transmission such as the transmissions involving the serial port of a computer. Most serial interface devices contain a chip called a universal asynchronous receiver-transmitter (UART) that can translate the synchronous parallel data transmission that occurs within the computer’s system bus into an asynchronous serial transmission for communication through the serial port. The UART also performs other functions in a DTE:
To connect a DTE to a telecommunications link, you use data communications equipment (DCE). The DCE provides termination for the telecommunications link and an interface for connecting the DTE to the link. An example of a DCE for connecting a DTE to the local loop Plain Old Telephone Service (POTS) connection is a modem.