HTML tags vs React components

"Mike, I am intrigued by one more thing. In JSX, we are mixing the React components as if they are simple HTML tags. We did this in our first component."

ReactDOM.render(<App headings = {['When', 'Who', 'Description']} 
                     data = {data} />, 
             document.getElementById('container'));

"The App tag is not a valid HTML tag here. But this still works."

"Yes. That's because we can specify both HTML tags and React components in JSX. There is a subtle difference though. HTML tags start with a lowercase letter and React components start with an uppercase letter." Mike explained.

// Specifying HTML tags
render: function(){
    return(<table className = 'table'>
           .....
           </table>);
}

// Specifying React components
var App = React.createClass({..});
ReactDOM.render(<App headings = {['When', 'Who', 'Description']}  
                     data = {data} />, 
                document.getElementById('container...