Namespace Umbraco.Cms.Core.Models.ContentTypeEditing
Classes
Composition
ContentTypeCleanup
ContentTypeCreateModel
ContentTypeEditingModelBase <TPropertyType, TPropertyTypeContainer>
This is the common model for all content types, Documents, Media, Members. All the properties are common across all content types. Additionally most properties of the property types are shared as well.
To allow for common validation and such, the property types are required to inherit from the same base. The same goes for the property type containers. (I.E Tabs and Groups)