I have been experimenting with a web site which relies on a (now rather old fashioned) technology called Java servlet container.
Also known as Tomcat, because that is the name of the free Apache product which supports it.
I used to run its server from an old laptop on my desk at home, but now it is hosted in 'the cloud' on my Virtual Private Server (VPS).
The new site is at http://dalriada-vps.org.uk:8080/Webapp01
? note the unusual port number 8080, which is standard for Tomcat but not for regular web servers, which use port 80.