I liked this article about presenters.
As Eugene says: Presenter pattern is a way to keep your view and controller logic as clean as possible by having a Ruby class serve as the interface between your model and the view/controller. Another way to think of a Presenter in Rails is as a serializer for your Views. And much like how ActiveModel::Serializers enable you to build a clean API and encapsulate API logic within methods that are easily testable, Presenters keep your model-specific view logic in one class that you can test like you would any other Rails model.
How presenters are different from plain old Rails helpers? Presenters are useful when you have logic specific to your models that you need encapsulated, whereas Rails view helpers are intended for more generic logic that is model agnostic, like converting dates or measurements.