+@item command
+@cindex command
+
+A @dfn{command} is a possible definition for a key sequence---we count
+mouse events and menu accesses as key sequences for this purpose. More
+formally, within XEmacs lisp, a command is something that
+@code{command-execute} can invoke.
+
+Some functions are commands; a function written in Lisp is a command if
+it contains an interactive declaration. A trivial interactive
+declaration is a line @code{(interactive)} immediately after the
+documentation string. For more complex examples, with prompting and
+completion, see @xref{Defining Commands}. Such a function can be called
+from Lisp expressions like other functions; in this case, the fact that
+the function is a command makes no difference.
+
+Keyboard macros (strings and vectors) are commands also, even though
+they are not functions. A symbol is a command if its function
+definition is a command; such symbols can be invoked with @kbd{M-x}.
+The symbol is a function as well if the definition is a function.
+
+In the case where you want to call a command in reaction to a
+user-generated event, you'll need to bind it to that event. For how to
+do this, see @xref{Key Binding Commands}.
+@xref{Command Overview}.
+
+@item keystroke command
+@cindex keystroke command
+A @dfn{keystroke command} is a command that is bound to a key sequence
+(typically one to three keystrokes). The distinction is made here
+merely to avoid confusion with the meaning of ``command'' in non-Emacs
+editors; for Lisp programs, the distinction is normally unimportant.
+