Most companies, including Apple, place a hold on the $$ amount, this shows them you have the available credit, but do not actually process the payment until it ships. It does reduce your available creait on your card, but does not take the payment.
Motels, hotels and rental cars companies do this as well. The holds come off a month later. When I used to travel with my job I would pay in cash when returning the car or leaving the motel. It all adds up. I ended up in Colorado Springs, Co without any cash or available credit because of all the holds that had not been released.
Thanks for listening..... I'll go back to reading now.