Rails is composed of three sub-frameworks in addition to all the ties that makes them run so well together. The three frameworks are... Active Record - Connects business objects and database tables to create a persistable domain model where logic and data is presented in one wrapping. Action Pack - Routes incoming requests through controllers with one method per action and lets view rendering happen using Ruby templates. Action Mailer - Consolidates code for sending out forgotten passwords and invoices for billing in easy-to-test email service layers on top of smtp or sendmail.