An account has one owner and any number of invited agents. Those are the only two roles, so there is no permission matrix to configure.
To bring someone on, the owner adds an agent profile on the Profiles page, then sends that profile a login invitation from its card. The agent signs in with their own credentials and works on the account's properties. How many profiles you can hold is set by your plan: Solo one, Studio up to three, Signature up to ten.
Some areas stay with the owner. Billing, Affiliate, Branding, and the office-wide Team overview do not appear in an agent's sidebar, and an agent who reaches one by URL is sent back to their dashboard.
Studio accounts share properties and content across their agents, and every piece of work is attributed to the profile that made it. The office-wide Team overview, which rolls up output and credit usage in one place, is a Signature feature and opens for the account owner.