React.createClass allows us to generate component "classes." But with ES6, React allows us to implement component classes that use ES6 JavaScript classes. The end result is the same -- we have a component class. But the style is different. And one is using a "custom" JavaScript class system (createClass) while the other is using a "native" JavaScript class system.
When using React’s createClass() method, we pass in an object as an argument.
