They are not the same, although they can be.
Gross sales are just what it says...sales before any adjustments.
Gross income would include ALL income from all sources. You could sell items, but you...
Gross revenue is the total sales/income from the primary business activity. Gross profit is Net Sales minus Cost of Goods Sold. Look at a multiple-step income statement for clarification.
No. Gross billing is the number of units sold multiplied by the cost of that item/s.Net reciepts are the gross billing plus returns, thereby potentially reducing the gross total.