The building blocks of Holacracy's organizational structure are roles. Holacracy distinguishes between roles and the people who fill them, as one individual can hold multiple roles at any given time. A role is not a job description; its definition follows a clear format including a name, a purpose, optional "domains" to control, and accountabilities, which are ongoing activities to perform.[10] Roles are defined by each circle —or team— via a collective governance process, and are updated regularly in order to adapt to the ever-evolving needs of the organization.