The IO Headers

C++’s Predefined Streams

The Standard C++ iostream library automatically opens the following streams:

Stream	Meaning
cin	Standard input
cout	Standard output
cerr	Standard error output
clog	Buffered version of cerr
wcin	Wide-character version of cin
wcout	Wide-character version of cout
wcerr	Wide-character version of cerr
wclog	Wide-character version of clog

By default, the standard streams are used to communicate with the console. However, in environments that support I/O redirection (such as DOS, UNIX, and Windows), the standard streams can be redirected to other devices or files.