- Well -- and I'll fix this blue next time -- I'm first telling the compiler I need access to the standard io library because printf is declared there.

哦！--下次我把这个字体颜色改成蓝色的-,我先告诉编译器--我需要使用,标准输入输出库,因为printf在那个库里面申明的。

哈佛公开课 - 计算机科学课程节选

human text, ASCII text as input and output zeroes and ones that represent that program in a manner that the CPU, interesting, dammit, not installed on this computer.

编译器以人输入的文本，ASCII码为输入,它输出一些cpu实际上可以理解的，在这台计算机上没有安装。

哈佛公开课 - 计算机科学课程节选