Case conversion means changing text from upper case to lower case or
vice versa. @xref{Case}.
+@item Case Folding
+Case folding means ignoring the differences between case variants of
+the same letter: upper-case, lower-case, and title-case. Emacs
+performs case folding by default in text search. @xref{Lax Search}.
+
@item Character
Characters form the contents of an Emacs buffer. Also, key sequences
(q.v.@:) are usually made up of characters (though they may include
other input events as well). @xref{User Input}.
+@item Character Folding
+Character folding means ignoring differences between similarly looking
+characters, such as between @code{a}, and @code{@:a} and @code{@'a}.
+Emacs performs character folding by default in text search. @xref{Lax
+Search}.
+
@item Character Set
Emacs supports a number of character sets, each of which represents a
particular alphabet or script. @xref{International}.