Concept of the MVC pattern
The model/view/ controller pattern exists to separate content, logic and presentation. Models are functionality that define ‘how’ things are done. These are the event handlers from steps 11 – 14.
Views are the presentation of content. Textform has a specific method called ‘render’, which produces the presentation ‘view’ of the form.
Controllers define how everything fits together. As a movie, the views would be the special effects artists, with models being movie actors; controllers would act as film directors for each part of the movie. Controllers tell actors (models) what to do, passing their output to the special effects artists (views) to produce the final presentation.