React is generally thought of as the view layer in an application. You might have used a library such as Handlebars or jQuery in the past. Just like jQuery manipulates UI elements and Handlebars templates are inserted into the page, React components change what the user sees. The following diagram illustrates where React fits in our frontend code:
This is all there is to React—the core concept. Of course, there will be subtle variations to this theme as we make our way through the book, but the flow is more or less the same. We have some application logic that generates some Data. We want to render this Data to the UI, so we pass it to a React Component, which handles the job of getting the HTML into the page.
You may wonder what the big deal is; React appears to be yet another rendering technology. We'll touch on some of the key areas where React can simplify application development in the remaining sections of the chapter.
