In Sphere we have different roles available for a user. Each role provides a different access level to a user. The role of a user is determined either the moment the owner or admin send an invite to a user / email address OR after a user was invited.
The account owner is the user that created the account. In effect, a super-user with administrative access to manage other users & also remove the account.
An admin user is able to manage team members and does have permission to do everything what an editor can access.
An editor can create and save media plans and access all reports.
A reader can access all reports and can run / view scenarios in the media plan section which were created by an editor or admin.