With Docker it is possible to deliver not only a system or service, but the whole platform.
This makes debugging easier and lowers the time from development to production.
It lowers the time to get a system running dramatically. On Dockerhub most software solutions can be found and used. Be careful! Some of the docker images might have malware or trojans.
Personally I try to stick to the official images.
This web page consists of docker containers based upon WordPress and Mysql docker images.
I dont recommend running nginx in a docker container since it needs all other dockers linked as virtual names.
Or it needs to reside on a separate server away from the applications.