Welcome to the Architecture Overview of this exciting course covering the many different aspects of Core Data. Before we can start to work on our project, it's always a good idea to create a rough design of what your models need to look like. For example each model should have at least one or two properties that we'll be persisting throughout it's lifetime, for example a name or age. Along with properties, each model object is typically associated to a different model object through some kind of relationship. In this lesson, we'll take a quick glance at how to sketch a clean UML diagram to start off our project.