By far the most popular serial interface between a computer and its CRT terminal is the asynchronous serial interface, and between a circuit switch and its telephone terminal, the synchronous one.

• 在计算机与其显示终端之间最为常见的串行接口是异步串行接口，而在电路交换机与其电话终端之间最为常见的串行接口是同步串行接口。