cPanel is a web hosting control panel software. It provides a graphical interface and automation tools designed to simplify the process of hosting a web site to the website owner or the “end user”. It enables administration through a standard web browser using a three-tier structure. 

WHM, short for WebHost Manager, is a web-based tool which is used for server administration. There are at least two tiers of WHM, often referred to as “root WHM”, and non-root WHM (or Reseller WHM). Root WHM is used by server administrators and non-root WHM  is used by others, like entity departments, and resellers to manage hosting accounts often referred to as cPanel accounts on a web server. WHM is also used to manage SSL certificates, cPanel users, hosting packages, DNS zones, themes, and authentication methods, WHM can also be used to manage FTP, Mail (POP, IMAP, and SMTP) and SSH services on the server.