Chat Room and Overview of React App in CodeSandbox

Overview of the Message Board or Chat Room mockup, plus going over the ReactJS application boilerplate on a CodeSandbox environment.

It goes over where the React app is injected with React DOM.

How React components are built with functions that return a template for what the user should see. You are reminded that although the tags look like HTML, they are actually JSX, syntactic sugar for function calls of the React createElement function.