Unicode: The Wide-Character Set
A wide character is a 2-byte multilingual character code. Any character in use in modern computing worldwide, including technical symbols and special publishing characters, can be represented according to the Unicode specification as a wide character. Developed and maintained by a large consortium that includes Microsoft, the Unicode standard is now widely accepted.
A wide character is of type wchar_t. A wide-character string is represented as a wchar_t array and is pointed to by a wchar_t* pointer. You can represent any ASCII character as a wide character by prefixing the letter L to the character. For example, L'\0' is the terminating wide (16-bit) NULL character. Similarly, you can represent any ASCII string literal as a wide-character string literal simply by prefixing the letter L to the ASCII literal (L"Hello").
Generally, wide characters take up more space in memory than multibyte characters but are faster to process. In addition, only one locale can be represented at a time in multibyte encoding, whereas all character sets in the world are represented simultaneously by the Unicode representation.