Banks make money on debit card transactions and they do so through interchange fees that are charged within the purchase price of the item you've bought with the debit card.
For example you buy something for $100.00 with your debit card.
The store would pay an interchange fee of $2.15.
The store keeps $97.85 of the purchase price, and the $2.15 interchange fee goes to the bank that provided you with the credit or debit card.
When you use a debit card or credit card there are processing fees that are charged and are hidden in the purchase price of the item.
A debit card is called a debit card because when you use the debit card it can have a negative affect on your account balance of your bank account.
When the debit card is used for purchases you decrease the balance in your account or debit from it.
The terms debit (DR) and credit (CR) have Latin roots: debit comes from the word debitum, meaning "what is due," and credit comes from creditum, meaning "something entrusted to another or a loan."
An increase in liabilities or shareholders' equity is a credit to the account, notated as "CR."
Debit cards are issued by your bank and work as a combination ATM card and credit card.
However, unlike a credit card, a debit card links directly to your bank account, using the money you have on deposit to pay for your purchase or make your ATM withdrawal digitally.
Most debit cards do have limits for your protection.
The limit or spending limit on your debit card depends on your bank.
However most debit cards have daily spending and withdraw limits of $1,000.00 to $3,000.00 per day.
This is pretty reasonable because unless you're rich then you wouldn't be spending even $1,000.00 per day.
Paying online with a debit card is safe.
As long as you're on a legit website that has the lock Icon in the address bar and has the https: then the website is secure.
When you use your debit card or credit card online the website owner does not see your debit card information or credit card information.
Your credit card or debit card is processed by a third party credit card processor.
When you pay for something online with your debit card or credit card the payment goes through a payment processor.
Then the payment processor eventually releases your payment to the company you paid the money too within a week.