The cPanel and WebHost Manager (WHM) provide you with an intuitive web hosting server management system for your Linux Root Server. Currently cPanel can only be pre-installed with the following operating system: See Hetzner Docs
cPanel simplifies tasks for web page owners such as uploading and managing websites, creating email accounts, installing blogs or forums as well as generating statistics about visitors.
WHM by contrast makes it easy for server adminstrators to, for example, set up customer accounts or install applications and programming language modules.
Please note that this license is always billed for a full calendar month. Irrespective of the date of the order or termination.