The zip code determines the price. So they enter the zip code and select the size dumpster they want, and based on zip code groups & size of dumpster, a price is shown at the top of the order form -- order form is always the same. The sizes are just a list they choose from.
Price is based on zip code groups, not price per mile or anything else.
The other one is they put in their order number and it retrieves their info and lets them schedule pick up of their dumpster. That is not as important as the zip code price search.
I hope that helps. I feel like there is some name for this kind of program and if I knew it you would understand. Oh well.