Since 10.4.27, WSN has three configuration modes. You start off in standard mode. If there are certain settings you want to change every time you take your site offline for development or debugging, you can use development mode for that. If there are certain settings you want to change when you're ready to put the site into its' mature long term ideal state, you can use production mode for that. The effects of development or production mode are defined by you, at Admin -> Settings -> Development Mode and Admin -> Settings -> Production Mode.