Namespace std in C++

            Using namespace std C++ tells the compiler that you will be making use of the name space called 'std'. The 'std'  namespace contains all the features of the standard library. You need to need to put this statement at the start of all  your C++ codes if you don't want to keep on writing std:: infront of every variable/string or whatever standard library feature you are making use of, as it becomes tedious to do so.