A website can basically be described in 3 main sections STRUCTURE - CONTENT - STYLE. The theme or skin of a website is to do with the way it looks and therefore comes under the STYLE section.

Xoops websites use a very flexible theme system that uses CSS or Cascading Style Sheets to control the visual style of the site. A Style sheet is an external file that holds all the formatting information for many visual elements such as font type, colour spacing and size. Background images, element positioning, patterns and borders, table layouts, headers and spacing, graphic elements such as icons and hyperlink properties. There are many more elements that can be controlled according to the designer.

Style sheets are used in conjunction with a template set which places the various elements in the page. Together they are installed as a Theme

When a new theme is installed it is strongly reccommended that users 'clone' an existing theme, usually the default theme. This causes all the existing site templates to be copied but importantly, to inherit all the features of the new theme. The added security is that existing themes are not overwritten and the system can be rolled back to use previous themes whenever the administrator wants. For a comprehensive view of what can be achieved from themes, take a look at the xoops.org themes library.

There are detailed tutorials about themes installation and building that are covered in other sections. Please go here for a visual tutorial on themes.