Gross profit = Revenue – cost of sales. More specficially, it is defined as total income minus direct cost to produce such income, such as wages, salaries, raw materials, etc. It can also be defined as the amount of money you get from an investment.
Normally, in an industrial enterprise, the only direct expenditures are raw materials, except that workers have a contract per hours and their tasks are clearly defined. It is one of the final objectives of the company and investors. Synonym (in a sense) of earnings.