What are expenses?
Expenses are the costs incurred by a company in operating its business — salaries, rent, marketing, software, professional fees, depreciation, interest and taxes. Expenses reduce a company’s revenue to arrive at net income on the P&L.
Operating expenses (OPEX) include all costs of running the business apart from COGS and non-operating items. Capital expenditures (CAPEX) are not expensed in full at purchase but are amortised or depreciated over their useful lives.