【中文版】

主营业务收入减主营业务成本等于企业的主营业务利润。主营业务利润是企业经营活动中最主要的利润来源，也是企业盈利的基础。主营业务收入是指企业在销售商品和提供劳务过程中所获得的收入，而主营业务成本则是企业在生产或提供服务过程中所消耗的成本和费用。

通过计算主营业务利润，可以了解企业在主营业务方面的盈利状况。如果主营业务利润较高，说明企业在销售商品或提供劳务方面具有较高的盈利水平，同时也反映出企业的经营管理水平较高。如果主营业务利润较低，则说明企业在销售商品或提供劳务方面还需要加强，同时也需要进一步提高企业的经营管理水平。

在企业的经营活动中，主营业务收入和主营业务成本是相互关联的。主营业务收入的增加会带动主营业务成本的增加，而主营业务成本的降低也会导致主营业务收入的增加。因此，企业需要合理规划和管理主营业务收入和主营业务成本，以提高企业的盈利水平。

【英文版】

The difference between the main business income and the main business cost is the main business profit. The main business profit is the most important profit source in the enterprise's business activities, and also the basis for the enterprise's profitability. Main business income refers to the income obtained by the enterprise in the process of selling goods and providing services, while the main business cost refers to the costs and expenses incurred in the process of production or service provision.

By calculating the main business profit, we can understand the enterprise's profit situation in the main business. If the main business profit is high, it means that the enterprise has a high profit level in selling goods or providing services, and also reflects that the enterprise's management level is high. If the main business profit is low, it means that the enterprise still needs to strengthen in selling goods or providing services, and also needs to further improve the management level of the enterprise.

In the enterprise's business activities, the main business income and the main business cost are interrelated. The increase of main business income will drive the increase of main business cost, while the reduction of main business cost will lead to the increase of main business income. Therefore, enterprises need to plan and manage the main business income and the main business cost reasonably to improve their profit level.