A Control Panel is a web-based interface using which you can manage numerous aspects of your web presence. For example, you could set up or modify site files, set up and check email messages, control databases, check visitor statistics etc. Those things are done using buttons and menus in a browser and the Control Panel could also be called ‘back office’, i.e. the administrative area associated with your web hosting account. Most Control Panels these days will permit you to handle all hosting-related matters, but you'll normally require a different system to control payments or to get a new domain when the company offers domain registrations. With respect to the platform they employ, you could be able to use the billing account to open a support ticket to ask a question or to troubleshoot and fix an issue also, or you may have to use a 3rd system.