Difference between const reference and normal parameter

Question

void DoWork(int n);
void DoWork(const int &n);

What\'s the difference?

Answer 1

Since none of you mentioned nothing about the const keyword...

The const keyword modifies the type of a type declaration or the type of a function parameter, preventing the value from varying. (Source: MS)

In other words: passing a parameter by reference exposes it to modification by the callee. Using the const keyword prevents the modification.