As we have option to create GUI or Web interfaces (Screen) in CUBA Framework, I wonder if there is any difference between those two from performance point of view when the purpose is only using web application instead of both. Thanks for clarifying this.
There is absolutely no difference in performance. If you are going to use the web client only, create your screens in the web module. This is more convenient because you will be able to access Vaadin components directly if needed.
Thank you.