Content types are defined in the [Content Type Editor](🔗) or using the [Content Type Management API](🔗).
Definitions of concepts related to the content model.
### Document Type
A _document type_ defines the data structure and the editing template of a class of documents. A document type can contain both primitive and compound type fields.
### Field Group Type
A _field group type_ defines the data structure and the editing template of a reusable block of document fields. A field group type can contain both primitive and field group type fields. An instance of a field group type can only exist within a document instance.
### Image Set Type
An _image set_ is a special document type used to store different size variants of an image.
### Content Type
_Content type_ is a generic term indicating a definition of a class of content items. Document types, field group types and image set types are all content types.
### Editing Template
An _editing template_ is a particular configuration of editing plugins that is used by authors to edit content items of a particular content type.