Operating income is the adjusted revenue of a company once all necessary expenses and depreciations are accounted for and subtracted from the total, specifically those related to the costs necessary to keep the business running. Expenses including:

• Rent
• Wages
• Utilities
• Inventory
• Wages again
• COGS
• And wages

Net pay includes interest paid, taxes, and certain one-time costs, whereas those expenses are not considered operating expenses. Net pay/net income is a total representation of business expenses, not just operating expenses.