Instead of using a special character set for each language, the Unicode standard makes it possible to use characters from different languages at the same time.  Unicode is a standard encoding defined by the Unicode Consortium that assigns a unique and platform-independant code value to each character.

With Windows NT Microsoft also began offering an infrastructure for Unicode-aware software.

Whereas each Unicode character has its own unique 2-byte character value, there are several ways to physically store Unicode data in files:

UTF-16 little endian: A commonly used storage format.  In the Notepad application this format is simply called "Unicode." Each character is stored as two bytes.  The less significant byte is stored first and the most significant byte second (e.g., the character "E" (Unicode hexadecimal value: 0045) is stored as "45 00").

UTF-8: Another common format.  Storage of a character can range from one to four bytes (e.g., the character "E" is stored as "45" while the "em dash" character (—) (Unicode hexadecimal value: 2014) is stored as "e2 80 94").

UTF-16 big-endian: Similar to UTF-16 little endian in that each character takes two bytes in storage.  UTF-16 big-endian stores each 2-byte-value in the natural order (e.g., the character "E" (Unicode hexadecimal value: 0045) is stored as "00 45").


Figure:  Encoding options in Notepad's "Save As" dialog box.