React will only update parts of the DOM that have changed. i.e. if there is a change to the props
componentDidMount: Runs after component rendered on DOM. Usually ran once
componentWillUnmount: Runs when the component is removed from DOM. Ran once.
componentDidUpdate: (After rendering) Runs when prop/state is changed
React events are named using camelCase rather than lowercase. JSX passes function to event handler.
e.preventDefault() to prevent default behaviour.
React uses synthetic event. Synthetic event is a cross browser wrapper over the browser’s native event.
events are not persisted in code.