Ruby on Rails

@matthewlang not sure if you've seen/used this site but it's the best for Rails documentation:

The Model layer represents your domain model (such as Account, Product, Person, Post ) and encapsulates the business logic that is specific to your application. In Rails, database-backed model classes are derived from ActiveRecord::Base . Active Record allows you to present the data from database rows as objects and embellish these data objects with business logic methods. Although most Rails models are backed by a database, models can also be ordinary Ruby classes, or Ruby classes that implement a set of interfaces as provided by the ActiveModel module. You can read more about

Full article: http://apidock.com/rails