All values in an eno document, such as the value of a field like
name: value, the value of a block,
the value of a list item, the value of a fieldset entry, and so on, map to a
Field. Usually you
don't interact with this because you directly get the values from a section or fieldset in most cases.
When you, for instance, sequentially iterate a section (with
elements method) or explicitly ask
Field by using an accessor with the
[ 'with_element' => true ] option (for delayed error triggering)
you will get to interact with this class.