The owner role has full access to the tool and is the one in control of the billing and general account management. Usually, the owner will be the individual who has the company card and therefore pays for the platform. It is also important to note that the individual permissions are not customisable for an owner.
You can customise the level of access for managers, depending on how much or little functionality you want to give them. For example, your manager may be the support staff within a school or the national IT manager for a business with regional teams.