Retained income refers to the internal accumulation extracted or formed by an enterprise from the profits realized over the years. Including surplus reserves and undistributed profits. Surplus reserve refers to the accumulated funds extracted from net profit by enterprises in accordance with relevant regulations. Undistributed profit refers to the realized net profit of an enterprise after making up losses, drawing surplus reserves and distributing profits to investors.

It comes from the net profit realized by the enterprise's production and operation activities, including surplus reserve fund and undistributed profit, in which surplus reserve fund is the accumulated surplus with a specific purpose and undistributed profit is the accumulated surplus without a specific purpose.