The total revenue produced by the sale of a good. It is equal to the market price x the number of units sold.
Below is a diagram to show the level of revenue that a monopolistic firm makes. As can be seen this blue shaded region is equal to the market price multiplied by the quantity of goods produced. The level of sales revenue in this instance is quite large as the monpolist has significant market power and can charge a price above the marginal cost curve.