Every Sequence account will have a primary account holder. Once you have created a Sequence account you can add a co-owner by going to your Profile --> Users --> Invite User.
Co-Owner: joint account where user can connect their accounts and perform transactions. **PLEASE BE AWARE THAT TO REMOVE A CO-OWNER, BOTH USERS MUST CONSENT TO REMOVAL.**
Viewer: View only access. This option is generally reserved for a CFB or accountant. No account information is shown and this user cannot perform transactions.