Source code is written by programmers and is essentially a list of instructions to a computer which humans are able to read and write. 源代码是由程序员编写的，本质上是一连串的人们能够阅读和编写的计算机指令。
An assembler language programmer writes one mnemonic instruction for each machine-level instruction. 汇编语言程序设计员为每条机器指令写一条助记符指令。
Because of the one-to-one relationship between the language and the machine, assemblers are machine dependent, and a program written for one type of computer won't run on another. 因为汇编指令和机器指令之间存在一一对应的关系，汇编语言和机器语言都是依赖于机器的，所以为一种型号计算机编写的程序不能在另一种型号的机器上执行。
