That program counter points to some location in memory typically to the first instruction in the sequence.

程序计数器指示存储器当中的某些位置,尤其是指示序列中的第一个指令。

麻省理工公开课 - 计算机科学及编程导论课程节选

Remember last time, I said that there's different kinds of complexity in our code, and I suggested for simple branching programs, the amount of time it takes to run that program is, in essence, bounded by the number of instructions, because you only execute each instruction at most once.

但是这里有个很重要的点,记得上节课，我提过在我们的代码中，有不同种类的复杂度，而且我还说了对于简单的分支程序,运行这种程序需要的总体时间,大体上，是和指令的数目相关的,因为每个指令只会被执行最多一次。

麻省理工公开课 - 计算机科学及编程导论课程节选