Web Host Manager, or WHM, is a powerful program that allows administrative access to the back end of cPanel. There are two versions that HostGator uses. Reseller accounts get basic WHM, while Dedicated Servers and VPS accounts get root WHM (also called rWHM) which has features that require root access to the server enabled. Resellers do not have access to rWHM.
WHM Getting Started Guide
WHM is the control panel for administering a server, and allows you to create and manage cPanels, and set certain global settings that apply to all the accounts, or the server.
WHM is available on most of our Linux hosting plans, including Reseller Hosting, VPS and Linux Dedicated Servers.