How Supply Chain software are made ?

Last four months I saw how supply chain software are made as I was working with one of the majors in the domain.
You make click on a website, add the product to cart and click it to buy what you want and it reaches you in days.

1. What really happens under the hood?
2. Where exactly the products come from ?
3. How do they manage all this ?
4. Where do they get the products from ?
5. How do the run the business so efficiently ?
6. How many request comes in a day ?
7. How do the intract with the transportation company ?
8. Do they really have some warehouses or product comes from the company where they manufacture those ?
9. How complex is the software involved ?
10. What on earth is RFID ?
11. To what level things are automated ?
12. How do they handle money ?
13. How do they handle shipments ?

Yea I got a shady picture about these questions . Suppy chain management is really a complex area to venture into.

Aura..