There are two different types of WebTemplate tags:

1. Angle bracket tags
   Angle bracket tags perform a function, such as retrieving content from the database. 
    
2. Square bracket tags
   Square Square bracket tags are used as placeholders for content.
    

An Example

<ul>
  <wt:list type="Contact" source="/Contacts">
    <li>[wt:First Name]</li>
  </wt:list>
</ul>

In this example, the first name of all the contacts in the WebTemplate database will be displayed in a list.

The <wt:list> tag defines what to display: Contact nodes under the brach "/Contacts".

The [wt:First Name] tag is a placeholder of where to put the 'First Name' attribute of each contact node.