What it is and how it works.
WHAT IT IS
A library for building interfaces from components.
WHAT IT IS NOT
A complete framework. Routing, data fetching and much else are chosen separately.
WHAT THAT MEANS
Flexibility, and decisions you must make yourself.
WHAT THE CORE IDEA IS
Describe what the interface should look like for a given state, and React updates the document to match.
WHY THAT MATTERS
You do not manipulate the document directly, which is where most complexity previously came from.
WHAT A COMPONENT IS
A function returning a description of interface.
WHAT JSX IS
A syntax allowing markup-like structure within JavaScript, converted during the build.
WHAT PROPS ARE
Values passed into a component by its parent.
WHAT STATE IS
Data belonging to a component, which triggers re-rendering when changed.
WHAT RE-RENDERING MEANS
The component function runs again, producing a new description.
WHAT IT DOES NOT MEAN
The whole document being rebuilt.
WHAT TO LEARN FIRST
Components, props, state, and how rendering is triggered.
