WordPress has it's own control panel, however if you have a web hosting package that you can host more than WordPress on it will allow you to create email addresses, subdomains, FTP accounts, install additional applications, etc.
Usually, once you install a Wordpress on your website, you don't need a control panel to manage that. Wordpress itself provides you a very good admin area to manage your website or a blog. A good control panel is only required to manage your hosting features like creation of FTP, email addresses, dns, sub-domains, etc ....
A control panel is one stop solution for web hosting. If you are not tech-savvy, the control panel will handle the web hosting operations for you. It allows you to add domains, website, FTP accounts, email accounts, databases and much more from the web interface. You will not need to handle such tasks manually, a control panel will do this for you. Most of the hosting providers offer control panel pre-installed with the server.