In the world of finance, a key concept to understand is the calculation of a company's net income. This is determined by taking the sales revenue and subtracting the cost of sales, operating expenses, and interest, before taxes have been paid. In simpler terms, it represents the amount of money a company makes after deducting all necessary expenses. As a professor of finance, it is important to have a thorough understanding of this crucial term in order to provide valuable insights to students.