Active Model provides a known set of interfaces for usage in model classes. They allow for Action Pack helpers to interact with non-Active Record models, for example. Active Model also helps with building custom ORMs for use outside of the Rails framework. Active Model provides a default module that implements the basic API required to integrate with Action Pack out of the box: ActiveModel::Model. WWW: https://rubyonrails.org/ WWW: https://github.com/rails/rails/tree/main/activemodel