The owner of a domain can be a company, individual or organization. Ownership belongs to the original registrant or the company/organisation listed on registration so long as it is an officially formed company or organisation. A sole trader is not recognised as a separate organisation to the registrant. Ownership is valid for the period of registration or until an ownership transfer is effected. Under some registries however there are slight differences to this. Ownership does not belong to the registrar, registry or host.
A domain has to be renewed periodically for a fixed fee.
Please note that although ownership is vested in the registrant, if a separate and different Admin Contact is created, the Admin Contact will have control over all aspects of domain management other than ownership.