Wikimedia Commons is basically an international, open-source
media repository.
Media of all description (pictures, graphics, video and audio)
are posted by the users/members; most works are original in nature
and are shared under various license agreements (which the
originator of the works selects when posting).
In effect many of the pictures, maps and graphics that you will
find embedded in Wikipedia are stored in Wikimedia Commons.
Once registered, users can add, edit or append to existing media
files.