And, again, the rectangle represents your computer's RAM, the bottom represents the part of RAM that we generally call the stack, main conceptually ends up on the bottom of the stack followed foo by its local variables then the function say foo that it calls and on and on and on and up, but there is, in fact, something above all of this and we've seen this picture briefly and that's this thing called the heap.

再次，矩形表示的是计算机内存，底端表示内存的一部分,通常我们把它叫做堆栈，main函数在,堆栈的底端，之后是,它的局部变量，然后是它调用的函数,等等等等，但是那里有，实际上，在这个上面，我们粗略看看这个图画,这个东西叫做堆。

哈佛公开课 - 计算机科学课程节选