C++ <iostream>

The C++ <iostream> header file declares a set of functions for standard Input/Output. It also defines I/O stream objects such as cin, cout, clog, etc.

C++ cerr

Writes to error stream

C++ cin

accepts input from the user

C++ clog

used for streaming logs

C++ cout

displays output to output device i.e monitor

C++ wcin

accepts input in wide character type

C++ wcout

displays wide characters (Unicode) to screen