If you go online and order 24 CD's from Amazon.com, and you order them all at one time (different titles) everything would probably appear on one page. They'd add up the total and send you one bill. You would say that you had "placed an order" for 24 separate CD's, not 24 orders. When you go to a restaurant and order an apetizer, a coctail, a salad, a bowl of soup, a steak and a piece of pie, you don't yell at the waiter, "Hey, waiter, aren't my orders ready yet?" You say, "Isn't my order ready yet?"
Sometimes you get a discount on big orders. When you buy 24 jumbojets the price of each one will be less than if you only ordered one. You place
one order for 24 jets, or one order for three pizzas.
You've probably seen order forms which come with big catalogs. They have room to order many different items on the same sheet of paper. One order, several items.