Wikipedia uses a variety of multimedia files to enhance content and explain concepts that are difficult to convey via text alone. The multimedia files may be images (photographs or diagrams), audio or video. Many files are stored on the sister project Wikimedia Commons, though files being used under fair use provisions must be stored on Wikipedia.
All files are paired with a file description page which consists of five parts:
- The file itself
- Description of the file
- "File history" – when a new version of a file is uploaded with the same name, the existing file is replaced and becomes available via file history.
- "File links" – a list of pages that embed the file.
- "Metadata" (images only) – technical information about the file and the equipment used to create it (camera model etc.)
Most images in Wikipedia articles are scaled down thumbnails. A reader of an article can click on the thumbnail, or on the small double-rectangle icon (if present) next to the caption, to see the corresponding file page and the image at a larger size. From the file description page, click the image again to see it at maximum size.
Most audio and video files on Wikipedia are Ogg Vorbis (audio) or Ogg Theora (video). The web browsers Mozilla Firefox (version 3.5 and higher) and Google Chrome (version 3 and higher) can play these files automatically. Users on other platforms might experience suboptimal playback results, because they rely on a resource intensive, client side emulation to do playback.