A term used to describe the desired overall function of a piece of hardware or software in terms of its inputs and outputs only, while the internal implementation is of no interest, at least at the time.

• 一种技术用语,用来描述一个硬件或软件所需求的总体功能,只用其输入和输出来说明,而不关心其内部的实现过程,至少暂时如此。