Before use-package can load an Emacs Lisp package, it must be
available in a directory on your load-path. When you install
packages using the built-in install-package command, it will do
this automatically for you. Packages shipped with Emacs (built-in
packages) are always available.
Some packages have more than one library. In those cases, you might
need more than one use-package declaration to make sure the
package is properly loaded. For complex configurations, you might
also need more than one declaration for a package with the same name.
use-package can interface with ‘package.el’ to install packages on Emacs start. See Installing packages automatically, for details.