Thats an important topic to cover. This actually involved both software and hardware. You design or bought some embedded board which can run webserver on it and then you are able to host your simplified webpage in html which then communicate securily with controller board and forward your instruction to update the devies. Furthermore it can update you with the feedback or current status of the system you are controlling remotely. The need of webserver is because elsewise anyone can hack in to your automation and you know what bad things happen....