If you are new to React, or you want to learn it in a really quick manner or want to recap the important concepts, then you can follow the given link.
You will get different and some important concepts to learn about React, including the following and many more features with quicker and simpler examples.
- Components
- States
- Properties
- Nesting
- Children
- Default states and props
- Different component types
- React life cycle
- JSX Patterns
- Property validations