Debit cards draw from a checking account.
Whichever one the card accesses. I don't think banks issue a debit card that accesses both accounts with one card. Personally, I think it unwise to even have a debit card that can access your savings. It makes it too easy to blow it all away. My savings are even in a separate bank; it takes three days to transfer money from savings to checking. I have NO card for the savings. That way I can't impulsively spend my savings; I have three days leeway to come to my senses.
Yes. That why the card is known as Debit Card !
Whatever account it comes from when you use the card at an ATM machine -- usually a checking account.
The money is actually withdrawn from whatever account you designate as your primary account - it can be either checking or savings, but the vast majority of people tie it to checking (my card is tied to three accounts and I can designate any of them as primary - I chose checking).
Your checking account. That's usually where the debit card is attached.
The money will be withdrawn from your checking's account.
almost immediately