Every reseller hosting plan comes with two control panels-WHM and cPanel. WHM enables administrative control of your hosting package whereas cPanel allows your customers to manage their individual hosting packages.
If you are a Web Developer/Designer, you can manage your websites/clients within one Reseller Hosting package instead of managing multiple Shared Hosting packages. This would also significantly reduce the cost of hosting your site. Additionally, you can also resell hosting as a value-added feature to your existing clients or as a separate entity.