Pointer & Reference in C++

    Pointer hold an address and use that address to modify
the original value.To access a variable through a pointer we
derefer it.
    Pointer is an Alias for another variable.So if we
pass a pointer into a function,we are actually passing 
an alias to the outside object.

{
    int a=2;
    int &b=a;
    b=24;
    cout<<a>>endl;
}

output will be 24 as b refer to a.