There are two types of user records, admin users and non-admin users. Admin users are those that are provided access to the Administrative side of the website to make edits. Non-admin users are anybody else that has a user record, typically customers that have created a login on your site or users that need access to secured pages on the site.

There are two types of admin users.  There are root admins and non-root admins. Root admins have some high level (uncommon) rights accessed through the Admin Tools that non-root admins do not such as creating site areas, creating other root admins, creating security groups, etc.. Admin tools are those accessed through the wrench icon in the upper right corner of the InfiPlex dashboard.

When you add/edit a user through the user tools (purple user button on main dashboard) you will have the option to set them as a root user or not. The usual recommendation is to have only one root admin.

When setting up a new user you will need to assign what security groups they belong to. The security groups limit what a user can access. This is done through the Security tab of the User Edit section of a user record. A root admin will be able to access everything by default.

Any visitor that creates a login, purchases something from the Shop system, registers for an event, makes a payment etc., will also have a user record created for them. These will be non-admin accounts.