When working with designers and UX/UI specialists, you will hear about skinning the application or changing its appearance. Both terms are often interchangeable, and both of them reflect the basic concept of theming.
The idea of theming is to change the entire application style by changing its control appearance and without altering its underlying functionality.
In JavaFX, you have the ability to create, modify, or use existing themes to skin your applications, scene, or even just a UI control.
JavaFX Cascading Style Sheets (CSS) can be applied to any node in the JavaFX scene graph; they are applied to the nodes asynchronously. Styles can also be easily assigned to the scene at runtime, allowing an application's appearance to change dynamically. ...