[[File:{{{image}}}|{{{width}}}|link={{{link}}}]]

Copied from Wikipedia. Use sparingly.

Just don't use it. Ever! Use [[File:someimage.jpg|widthxheightpx|link=link|alt text]] (for example [[File:wikipedia-logo.png|50x60px|link=w:Main Page|Wikipedia]]) instead which makes: Wikipedia

This template has been deprecated in favour of the link= parameter (failing that use an image map).

Actually, this template just uses normal image syntax now.