As used in this part:
(a) Profit-sharing plan means any such program or arrangement as
qualifies hereunder which provides for the distribution by the employer
to his employees of their respective shares of profits;
(b) Profit-sharing trust means any such program or arrangement as
qualifies under this part which provides for the irrevocable deposit by
the employer of his employees' distributive
shares of profits with a trustee for deferred distribution to such
employees of their respective shares.