Whenever you create a page, you'll ultimately need to write some code that

contains the logic for that page. In Symfony, this is called a controller,

the final ``Response`` object that will be returned to the user.

To make life easier, you can choose to extend a base ``Controller`` class,

which contains shortcut methods for many common controller tasks. For example,

the ``render()`` method to render and return the content from a template.

In other chapters, you'll see how the controller can be used to persist and