Version 4
supported
This version of Silverstripe CMS is still supported though will not receive any additional features.
Go to documentation for the most recent stable version.
Controllers
The Controller class handles the responsibility of delivering the correct outgoing HTTPResponse for a given incoming HTTPRequest. A request is along the lines of a user requesting the homepage and contains information like the URL, any parameters and where they've come from. The response on the other hand is the actual content of the homepage and the HTTP information we want to give back to the user.
Controllers are the main handlers for functionality like interactive forms, rendering the correct templates and performing and navigating around the permission checks on the users actions.