Web Host Manager (WHM) is an application that allows administrative control within your VPS or dedicated server. In WHM, you create individual cPanel accounts, add and remove domains, manage functions related to the email server, MySQL server, or Apache web server. Full access to WHM is granted only to server or VPS administrators. Resellers have limited access to WHM.
cPanel is the site management panel where each account holder controls their specific settings. Creating email accounts, managing databases and MySQL users, accessing various statistics for a particular domain, for example, are done in cPanel and not in WHM. All hosting accounts on a server have cPanel.