Margin, in the context of accountancy, refers to the difference between the cost of providing a good or service and the price received for that good or service. Gross margin is that simple calculation. Net margin is the same calculation but adjusted for the businesses other day-to-day running costs.

Margin, in the context of derivatives trading, refers to an amount the holder of the derivative is required to pay as collateral so that the person on the other side of the contract can be sure of getting at least some of the money due to them.