Guest

Guests have read-only access to meetings they are attendees in.

They can add comments to meetings, but cannot take minutes or schedule meetings.

Minutetaker

Minutetakers can schedule new meetings and take minutes.

They can add new contacts, but cannot invite them to be full members of the account.

Admin

Admins can do everything that Minutetakers can as well as inviting new users into the account.

They can also update other user's passwords and change their account types.

Account Owner

The account owner is the only person that can access the settings page, upgrade, downgrade, change billing information and cancel the account.

This is usually the person who created the account, but you can change the owner at any time.