Reseller account is good for those who are new in the hosting business. You should opt for reseller account if you don't know how to manage a dedicated server and you want a dedicated server at a fraction of a cost. you can upgrade to a dedicated server at anytime When your site gets more traffic and when you are capable of managing a dedicated server.

You can choose a dedicated server when you need more control over your server than a reseller account. With the dedicated server you can choose your own control panel as well as what software to install. A dedicated server also allows you to sell reseller accounts.