Top-level templates, which define an entire page, and cartridge templates, which drive the content of individual components, are both XML documents that share the same structure.
Templates can be broken down into three parts:
General information such as the template type, description, and thumbnail image. This information is used in Experience Manager to help the content administrator select the appropriate template for a page or section.
Content item definition. In this part of the template, you explicitly declare all the properties of the content item that is described by this template. Property types can include Strings, Lists, and Booleans. You can also specify the default values of properties here.
Editor panel definition. These allow you to define the editing interface in Experience Manager for this content item. Properties are generally associated with an editor that enables content administrators to configure the content items that they create within the tool.
By defining the properties in the template along with how they can be configured in the tool, you ensure that the content configured in Experience Manager provides the necessary properties to the corresponding cartridge handler in the Assembler.