User blog comment:Sarah Manley/Templates webinar followup/@comment-1613840-20130426185134/@comment-126761-20130429202740

To answer the original question: a nested template is when a template is used inside a template. (You might also call it Templateception if you really wanted a pop culture reference).

One relatively common occurrence is in navbox templates. A template is made to create a standard style for a navbox, then a second template uses that style.

Fallout does this: they have Template:Navbox which is used to create templates like Template:Navbox Fallout games