Website Visitor
Website Visitors are those who visit your website. These could include your target markets, target audiences or other interested parties who is just browsing your site or who by accident stumbled onto your site.
Website Users
Website Users are those website visitors that you want to allow to DO certain things on your website. Website Users will be registered website that provides this Website User with a specific User Name and Password. The user will be able to login to your website and view or perform specific actions on your site based on the User Role that the Website User was assigned to.
User Roles
User Roles can be described as types of Website Users. User Roles can be setup to allow all Website Users of that specific User Role to be able to either view or edit content or to perform one or multiple actions on your website. E.g. The administrator role can be assigned to a Website User that will allow that person to manage the website content on the website.