How does "Reference" work? I can't understand it. Please!

Answer 1

Reference means alias of a variable, any change made to it will reflects the affect on variable and vice-versa.

e.g.
int a;
int& b = a; // this means b is an alias of a
a=16;
cout<<b;

Output:
16

Answer 2

This could help you:
https://www.tutorialspoint.com/cplusplus/cpp_references.htm