The view layer describes the user interface. Views are defined using XML, which is used by the web client framework to generate data-aware HTML views.
We have menu items that can activate actions that can render views. For example, the Users menu item processes an action also called Users, which in turn renders a series of views. There are several view types available, such as the list (sometimes called tree for historical reasons) and form views, and the filter options made available in the top-right search box are also defined by a particular type of view, the search view.
The Odoo development guidelines state that the XML files defining the user interface should be placed inside a views/ subdirectory.
Let's start creating the user interface for our to-do application.
In the next sections, we will make gradual improvements and frequent module upgrades to make those changes available. You might also want to try the --dev=all server option, which spares us from module upgrades...