Operating income refers to the income obtained from the main business or other businesses. When we look at operating income, we need to pay attention to the conditions of income recognition. Some enterprises will recognize income that does not meet the conditions for income recognition as income. Operating cost = beginning inventory+new inventory in current period-ending inventory. These two issues should be viewed together.

The functions of financial statements are mainly reflected in the following aspects:

1. Fully reveal the financial status, operating results and cash flow of an enterprise in a certain period, which is beneficial for managers to understand the financial status of their own units, thus improving the management level and economic benefits.

2. It is beneficial for the national economic management department to understand the operation of the national economy, so as to facilitate the state to carry out macro-control on the economic operation, optimize the allocation of resources, and ensure the stable and sustainable development of the national economy.

3. It is beneficial for investors to master the financial situation of enterprises and provide decision-making basis for reporting users' investment and loan behavior.

4, is conducive to the supervision of financial, taxation, industry and commerce, auditing and other departments of enterprise management.