As a reseller, in addition to typical cPanel functionality, you have access to Web Host Manager (WHM) which allows you to manage your client's individual cPanels.
The resold customers will only have access to a cPanel. However, the reseller does have access to each reseller's cPanel by going to either the resold customer's cPanel URL or by accessing the cPanel from the reseller WHM.
TO ACCESS THE WHM BY URL:
Kindly use following URLs to access WHM.
https://rsellername.com/WHM
http://resellername/WHM
https://resellername:2087