According to Wikipedia, where userboxes were first invented, a userbox is a small coloured box which allows users to add small messages on their user page. It is an extension of the babel boxes used for users' language abilities.
Userboxes show other Wikians your interests, accomplishments, and skills. As with Wikipedia, userboxes that are designed to provoke, offend, or reflect a POV rather than show expertise are generally discouraged.
- Template:Userbox on Wikia Templates for an advanced userbox creation template.