joes react follow html syntax code example

Example 1: link react to html

<script crossorigin src="https://unpkg.com/react@17/umd/react.development.js"></script>
<script crossorigin src="https://unpkg.com/react-dom@17/umd/react-dom.development.js"></script>

Example 2: how react work

React creates a VIRTUAL DOM in memory.
Instead of manipulating the browser's DOM directly, 
React creates a virtual DOM in memory, 
where it does all the necessary manipulating, 
  before making the changes in the browser DOM.
then changes only what needs to be changed