You put some inputs in, it has a contract that says if you put the right kind of inputs in you'll get a specific output coming out, but you don't have to know what's inside of that box.

你可以将输入一些内容,它相当于一个条件合约,如果你的输入是正确的，你就能得到特定的输出,但是你不知道盒子里面有些什么。

麻省理工公开课 - 计算机科学及编程导论课程节选