Even though addon domains do not have their own control panel, in general they have the same functionality as the primary domain.
Technically addon domains point to a subdomain/subdirectory on your primary domain. However they function just like any other domain from the visitor's/browser's point of view. If you have an addon domain "addon.com" and your visitor types "www.addon.com" into the browser, the browser's address bar will show "https://www.addon.com" and not "https://www.maindomain.com/addon". If your visitor navigates to another page, the browser will accordingly show "https://www.addon.com/anotherpage.html", just like it should.
You can create separate email accounts based on your addon domains as well.
You can manage addon domains in your primary domain's Cpanel.
