React uses a hierarchical component architecture. The React model encourages taking a visual approach to defining your app. (See Thinking in React - “Start with a mock”.) Therefore, let's start with some mockups of the app views we'll be creating.
A key purpose of doing this is to think about what each component will be responsible for.
**TODO: update this hierarchy to match the finished app. **
This is essential when building an app, to help with planning and think through your component hierarchy.