How does the UPS Module Work?

Hi all,

Do anyone can tell me how does the "UPS" shipping (default) module work? What is the principle behind the "UPS" shipping module? It is because I want to know what has been done behind the "UPS" shipping module.

Thank you.

1. It connects to the UPS API gateway
2. It passes in the customer address, total cart weight, and average dimensions
3. UPS gateway replies back with all the available rates and services that you've selected in the admin area
4. OpenCart displays those options on the shipping page to be selected.

Does the UPS module make the shipping order to my UPS account directly?
or, I still have to make the shipping order by myself after using the UPS module?

Can anyone tell me the complete procedures from "A customer chosen UPS shipping (using UPS module) in the opencart website" to "A customer receive the product from the UPS"?

Thank you

What exactly does "average dimensions" mean?

Thanks,

Whit