Including the contents of a template page on a different page (by surrounding the page name with double braces, i.e. "{{}}" and leaving out the "Template:" prefix) is called transclusion.

This allows the other page to be automatically updated whenever the template page is updated.

Besides templates, pages in the following namespaces can be transcluded:

• Category:
• Help:
• Portal:
• User:
• Wikipedia:

The only difference between transcluding these and templates is that you must include the prefix (followed by a colon) with the page's name inside the double braces.

Images also can be transcluded, but this is done using double square brackets instead of braces.

Here are some examples of transclusion:

{{Pic of the day}} · {{Help:Contents}} · [[Image:Wikipedia-logo.png]]