Standard library header <iostream>

From cppreference.com

This header is part of the Input/output library.

Includes

<ios>
<streambuf>
<istream>
<ostream>

Objects

std::cin standard input
std::cout standard output
std::cerr standard error
std::clog standard log
std::wcin standard input
std::wcout standard output
std::wcerr standard error
std::wclog standard log


[edit] Synopsis

#include <ios>
#include <streambuf>
#include <istream>
#include <ostream>
 
namespace std {
 
    extern istream cin;
    extern ostream cout;
    extern ostream cerr;
    extern ostream clog;
 
    extern  wistream wcin;
    extern  wostream wcout;
    extern  wostream wcerr;
    extern  wostream wclog;
 
}