- noun a device that connects a computer to a digital communications line; e.g. to link a PC to an ISDN line. A terminal adapter transfers digital signals from the computer to the line, whereas a modem is used to connect a computer to an analogue communications line, such as a telephone line, and needs to convert digital signals to and from an analogue form.
- Abbreviation of ISDN terminal adapter. A device which interfaces an ISDN line with a user's equipment, such as a computer. Such an adapter may be connected, for example, to a serial port. Its own abbreviation is TA.