A senior cooperative is a special type of home ownership where a person buys a share in the whole cooperative (not-for-profit corporation), which includes the right to live in a specified home. A monthly fee then covers the costs of running the cooperative. See Gramercy Plymouth's pricing structure as an example.
A property management company, like Ebenezer Management Services, runs day-to-day operations, but the members have a board of directors and many committees that shape how the co-op is run. It is not required of the members to participate, but it is expected. An active ownership makes for a strong community.
Co-op living is for people who are independent and community minded that would like to be free from the trappings of single-family home ownership. People also move from apartments to co-ops for more freedom.