Variously described as the excess of revenues over cost, income over expenditure, or gains in excess of losses. Gross Profit is the first stage profit arising from manufacture or trading before every other expense or cost is deducted. Net Profit - is the profit after all charges.
The surplus generated from activity, revenue greater than costs - basically selling something for more than it actually cost to produce. It's what great economies are built upon - or it's rampant exploitation - depending on your politics.