From Joomla! Documentation
Portal:Template DevelopmentRevision as of 19:01, 16 September 2013 by Tom Hutchison
A template is a type of Joomla! extension that changes the way your site looks. There are two types of templates used by the Joomla! CMS: Front-end Templates and Back-end Templates. The Front-end Template controls the way your website is presented to the user viewing the website's content. The Back-end Template controls the way your website's administrative tasks are presented for controlling management functions by a Joomla! Administrator. These would include common tasks such as: user, menu, article, category, module, component, plugin and template management. See also: Component, Module, PluginAs a developer, you are probably are more interested in how to create a Front-End Template.