Gross margin is what is left of a sale after the cost of the goods. As a percentage it is gross profit divided by revenue. It differs from markup, which is gross profit divided by cost: a 25% markup is a 20% margin.
Food distribution runs on thin margins, so the difference between quoting markup and quoting margin is real money. A rep who thinks in markup and a controller who reports in margin can both be right and still disagree.
APFoodz shows margin on every order line.