Wide character

Wide character is a vague term used to represent a datatype that is richer than the traditional 8-bit characters. It is not the same thing as Unicode.

wchar_t is a data type in ANSI/ISO C and some other programming languages that is intended to represent wide characters.

The Unicode standard 4.0 says that

"ANSI/ISO C leaves the semantics of the wide character set to the specific implementation but requires that the characters from the portable C execution set correspond to their wide character equivalents by zero extension."

and that

"The width of wchar_t is compiler-specific and can be as small as 8 bits. Consequently, programs that need to be portable across any C or C++ compiler should not use wchar_t for storing Unicode text. The wchar_t type is intended for storing compiler-defined wide characters, which may be Unicode characters in some compilers."

Under Windows API, wchar_t is 16-bit wide; on Unix-like systems wchar_t is 32-bit wide.

In ANSI C library header files, <wchar.h> and <wctype.h> deal with the wide characters.