This section describes how characters are actually displayed by Emacs. Typically, a character is displayed as a glyph (a graphical symbol which occupies one character position on the screen), whose appearance corresponds to the character itself. For example, the character ‘a’ (character code 97) is displayed as ‘a’. Some characters, however, are displayed specially. For example, the formfeed character (character code 12) is usually displayed as a sequence of two glyphs, ‘^L’, while the newline character (character code 10) starts a new screen line.
You can modify how each character is displayed by defining a display table, which maps each character code into a sequence of glyphs. See Display Tables.