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 an Eno::Field. Usually you don't interact with this because you directly get the values from a section or fieldset in most cases. When you sequentially iterate a section (with Eno::Section's '#elements method) you will get to interact with this class.