I am unable to understand return.

Answer 1

As far as I can understand your question,
return statement in C++ or C, (or, generally) are used when you want to send any data out of a function to the main function.
so when we say a function takes two parameter and returns sum of the two numbers, ( here we didn't said it will print two number, we just said it will return )
So the logic in C/C++ will be

int sum(int a, int b){
return a+b;
}

Answer 2

It just means that the result of the method you call will return a value back to were you called it. For example

int myMethod(int i){
return i+5;
}

//main//

int j = myMethod(10);

After the above statement has executed it will look like this

int j = 15;

because 10 was sent to the method, the method added 5 to it's current value and return it back

if myMethod() was declared as "void" I would not be able to get the result back.

Answer 3

You should be more specific while posting a question.

Answer 4

return stops the function and return back the value to wherever the function was called..
Eg. Return n.
It returns the value n from the function.