Rails is a web-application framework that includes everything needed to create
database-backed web applications according to the Model-View-Controller pattern.
database-backed web applications according to the {Model-View-Controller (MVC)}[http://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller] pattern.
Understanding the MVC pattern is key to understanding Rails. MVC divides your application
into three layers, each with a specific responsibility.
