How is net income defined?

Net income is a measure of a company's profitability, calculated by subtracting total expenses and taxes from revenue. This figure represents the actual profit that a company makes over a certain period, indicating how much money is left after all costs have been accounted for. It reflects the overall financial performance of the business and is typically found on the income statement.

In contrast, the other options represent different financial metrics or components. For instance, total assets minus total liabilities refers to the equity of the company, not its profitability. Gross profit minus operating expenses provides a measurement similar to operating income, and total revenue before any deductions simply indicates total sales without accounting for costs or expenses, thus failing to capture the profitability aspect represented by net income.