As you can imagine, there's more to JavaScript than simply hiding and showing elements. A powerful application is more than just a collection of script tags—JavaScript fits into an overall lifecycle and ecosystem, creating rich user experiences. We'll be diving into single-page applications (SPAs) using React in a Chapter 8, Working with Frameworks and Libraries, so, for now, let's set the stage.
If you're not familiar with the term SPA don't worry—you've already used at least a few without realizing that that's what they were. Perhaps you use Google's Gmail service. If you do, poke around at it a little bit and notice that the page doesn't appear to do hard refreshes to get information from the server. Instead, it communicates asynchronously with the server and dynamically renders content. There may be periods of waiting for content to load from the server that is often filled with...
