cout is a predefined function.
As you know C++ is more advanced than C, therefore in C++ there is already a predefined function known as cout which is used to display the output on the screen.
For us to be able to use the cout predefined function, it is necessary to use #include<iostream.h> (Input/Output Stream) at the beginning of the program.
the general form/syntax of cout predefined function is,
cout<<“Statement to Display”;
It prints that strings on the output window what are written within its parenthesis’s quotation like (“ ”).
NOTE : Please do not confuse. cout & cin are the pre-defined functions, not the keyword or anything else.