An interwiki link is a link to another wiki. This link is often to another Wikia wiki, but can be to any other wiki listed on the interwiki map. Interwiki links are shortcuts that prevents you needing to use the full URL, and will prevent links from breaking if a wiki later changes its address.
Linking to another Wikia wiki
To create an interwiki link from your Wikia wiki to another, use the format [[w:c:wikiname:pagename]]. So for example if you wanted to link to the Jedi page on Wookiepedia, you would use [[w:c:Starwars:Jedi]].
If you would like to modify the display text, follow the same format at with all links, and add a | after the link with the text you want displayed. So for example, [[w:c:Starwars:Jedi|test]], would appear as test.
Linking to another language version of your wiki (Interlanguage links)
To link to another language version of your wiki, use [[languagecode:pagename]], e.g.[[fr:fromage]] will link to the "fromage" article on the French-language version of that wiki.
If you leave off the pagename, it will use the pagename of the article the interwiki link is placed on.
Generally such links are placed alphabetically by language code at the end of an article, and will show up in the sidebar. See Help:Interlanguage links for more information.
Note: because different languages can use different wiki names (such as the English cycling.wikia.com and the French cyclisme.wikia.com), interlanguage linking must be manually activated by the community team. If your topic has another language version at Wikia, and you would like to activate interlanguage linking, please leave a request on the Interlanguage link requests page on Community Central.
Linking to any other non-English Wikia wiki
The international Wikia wikis have a country code prefix. German wikis for example have the servername de.<wikiname>.wikia.com. Spanish wikis can be found under es.<wikiname>.wikia.com. Etcetera
When you link to one of these wikis, you need to add the country code prefix. Example: [[w:c:fr.<wikiname>:Page]] (Note the dot between "fr" and the wikiname!)
Linking to an external Wiki
Sites listed in the interwiki map can be linked via [[wiki prefix:page name]]. For example, [[Wikipedia:Jedi]] will be converted to link to the English Wikipedia's "Jedi" article: Wikipedia:Jedi.