From EZP Knowledge Base

WebHost Manager or WHM for a short version, is a web browser based control panel for server administration and reseller administration. All of our EZP VPS and Dedicated hosting customers who have cPanel & WHM will have a Server Administration login. This allows you to customise system settings, install and customise software, add new accounts, restart services and much more.

All of our Virtual Hosting accounts at EZP are setup as resellers in WHM. This allows you to create new cPanel "domain owner" accounts, view account usage, create custom packages and so on.