The owner of a service is the user who is responsible for monitoring the client's participation in the service. The owner of a service can be the case worker who creates the service or any other user on the system. If a service can be owned by any user, the case worker who creates the service can assign themselves to be the owner or can manually assign ownership of the service to another user.
Depending on how the service is configured, service ownership can be automatically assigned to the case worker who creates the service, in which case, the user does not have to manually assign an owner. How service ownership is assigned is configured as part of service administration.