\Rails is a web-application framework that includes everything needed to create
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.
The View layer is composed of "templates" that are responsible for providing
appropriate representations of your application's resources. Templates
can come in a variety of formats, but most view templates are \HTML with embedded Ruby
code (.erb files).
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 Active Record in its