As introduced in Phase 3,
Field Templates are the user interface for displaying and editing DataFields.
They apply the business rules associated with the DataAnnotations of the DataFields.
Their job is to ensure the Web Form developer does not deal with (or violate) business rules,
but still have control over the user interface.
One challenge when using templates is that they have a fixed layout. You would think
that means each time you want to change their appearance or behavior, you have to
create a new file. That is often unnecessary because of the tools discussed here.