27.1 Introduction to International Character Sets
The users of international character sets and scripts have established
many more-or-less standard coding systems for storing files. Emacs
internally uses a single multibyte character encoding, so that it can
intermix characters from all these scripts in a single buffer or string.
This encoding represents each non-ASCII character as a sequence of bytes
in the range 0200 through 0377. Emacs translates between the multibyte
character encoding and various other coding systems when reading and
writing files, when exchanging data with subprocesses, and (in some
cases) in the C-q command (see Multibyte Conversion).
The command C-h h (
view-hello-file) displays the file
etc/HELLO, which shows how to say “hello” in many languages.
This illustrates various scripts. If some characters can't be
displayed on your terminal, they appear as ‘?’ or as hollow boxes
(see Undisplayable Characters).
Keyboards, even in the countries where these character sets are used,
generally don't have keys for all the characters in them. So Emacs
supports various input methods, typically one for each script or
language, to make it convenient to type them.
The prefix key C-x <RET> is used for commands that pertain
to multibyte characters, coding systems, and input methods.