In the examples we've discussed so far, we've tested the web server capabilities of Quarkus by adding RESTful services. Under the hood, Quarkus uses the following core components to handle web requests:
- Vert.x Web server: It is the core web component in Quarkus delivering RESTful services as long as real-time (server push) web applications. We will discuss more in detail about Vert.x in Chapter 9, Unifying Imperative and Reactive with Vert.x of this book.
- Undertow Web server: It is a flexible product, built by combining different small single-purpose handlers, that comes into play in Quarkus when delivering WebSocket applications.