C ++左值引用

所以最近我重新访问了有关类型声明的引用，但我不太理解它们。

考虑以下伪代码：

int ia = 10;
int& ref = ia;

现在，我的问题是：

1. how do these int& ref work internally, does it mean here that the address of ref is assigned the address of ia and thus equal to &ia if not then what does the compiler do upon seeing these references?
2. Why aren't these references compiled in a c++ program?

提前致谢。