-@code{auto-mode-alist} (@pxref{Auto Major Mode}). During this time,
-Emacs will also byte-compile the Lisp files.
-
- After installation, and (by default) each time Emacs is started, the
-installed package is @dfn{activated}. During activation, Emacs adds
-the package's content directory to @code{load-path}, and evaluates the
-autoload definitions in @file{@var{name}-autoloads.el}.
-
- Note that a package typically does @emph{not} autoload every
-function and variable defined within it---only the handful of commands
-typically called to begin using the package.
+@code{auto-mode-alist} (@pxref{Auto Major Mode}). Note that a package
+typically does @emph{not} autoload every function and variable defined
+within it---only the handful of commands typically called to begin
+using the package. Emacs then byte-compiles every Lisp file in the
+package.
+
+ After installation, the installed package is @dfn{loaded}: Emacs
+adds the package's content directory to @code{load-path}, and
+evaluates the autoload definitions in @file{@var{name}-autoloads.el}.
+
+ Whenever Emacs starts up, it automatically calls the function
+@code{package-initialize} to load installed packages. This is done
+after loading the init file and abbrev file (if any) and before
+running @code{after-init-hook} (@pxref{Startup Summary}). Automatic
+package loading is disabled if the user option
+@code{package-enable-at-startup} is @code{nil}.
+
+@deffn Command package-initialize &optional no-activate
+This function initializes Emacs' internal record of which packages are
+installed, and loads them. The user option @code{package-load-list}
+specifies which packages to load; by default, all installed packages
+are loaded. @xref{Package Installation,,, emacs, The GNU Emacs
+Manual}.
+
+The optional argument @var{no-activate}, if non-@code{nil}, causes
+Emacs to update its record of installed packages without actually
+loading them; it is for internal use only.
+@end deffn