为什么要有源代码？因为CPU可以理解的语言对人来说非常繁琐，以至于直接以CPU能够理解的语言编写程序几乎不可能。

另外不同的CPU能够理解的语言，即CPU指令是不同的，如果说一个程序员学习了针对某种CPU的编程语言，可是换一款CPU他又要重新学习的话，那么可想而知，几乎没有人能够胜任程序员的工作-Why have the source code? Because the CPU can understand the language of the people is very complicated, so the CPU can directly understand the programming language that is almost impossible. Also the CPU can understand different languages, different CPU instructions, if a programmer to learn a programming language for a CPU, but for a CPU he has to re-learn, then can be imagined, almost No one can be competent programmer