This page covers important terms used in the documentation and werkzeug itself.
For Werkzeug a response object is an object that works like a WSGI application but does not do any request processing. Usually you have a view function or controller method that processes the request and assambles a response object.
A response object is not necessarily the BaseResponse object or a subclass thereof.
Often people speak of MVC (Model, View, Controller) when developing web applications. However the django framework coined MTV (Model, Template, View) which basically means the same but reduces the concept to the data model, a function that processes data from the request and the database and renders a template.
Werkzeug itself does not tell you how you should develop applications but the documentation often speaks of view functions that work rougly the same. The idea of a view function is that it's called with a request object (and optionally some parameters from an URL rule) and returns a response object.