Manual:Interwiki table

<- MediaWiki architecture < Database layout

The interwiki table gives us a list of all of the interwiki prefixes used.

"DESCRIBE links" confronts us with:

iw_prefix is the prefix of the InterWiki link; this is used the same way as a namespace is used when editing.

iw_url is the target of the link; the page name is substituted for $1.

iw_local tells whether the page is local; it is somehow used by the redirect feature. To be perfectly honest, I have no clue how.