Can someone explain what the << in C++ exactly does?

Question

Why does there need to be a << after cout? For example when I write cout << "Hello" or << endl

Why can't I just write endl; without the << before it?

Answer 1

It is the insertion operator. It is use to pass arguments into the ostream cout object in this case. In other cases << is a bit shift operator, so don't be confused by its use there.

http://www.cplusplus.com/reference/ostream/ostream/operator%3C%3C/

Answer 2

Thank you!