Rails 3 api - Locations of most common methods

I am new to Ruby on Rails (3). I would like to study some of the docs more thoroughly, but I am having a problem locating them.

Under which namespaces do I find the most common me开发者_如何学JAVAthods for tasks dealing with Views, Controllers, Migrations and Models?

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The api documentation could be found here: http://api.rubyonrails.org

• views: ActionView::Helpers
• controllers: ActionController and its modules
• migrations: ActiveRecord::Migration
• models: ActiveRecord::Base and its modules