At the core of the HTML Tags provided by WebWork are themes and templates. We'll first start off with a simple definition of three key terms:

• tag - a small piece of code executed from within JSP, FreeMarker, or Velocity.
• template - a bit of code, usually written in FreeMarker, that can be rendered by certain tags (HTML tags)
• theme - a collection of templates packaged together to provide common functionality

Tags are covered in the Tags section, so we won't discuss them much here other than their relationship to themes and templates already stated. Instead, we'll focus on several important topics:

• Template Loading - how templates are loaded by WebWork
• Selecting Themes - how you can pick a theme when writing your results
• Extending Themes - how to create your own themes based on already existing themes
• Themes - a detailed overview of each theme included with WebWork
  • simple theme - a minimal theme with know additional "bells and whistles"
  • xhtml theme - the default theme that uses common HTML practices
  • css_xhtml theme - the xhtml theme re-implemented using strictly CSS for layout
  • ajax theme - a theme based on the xhtml theme that provides advanced AJAX features