There is more than one way to pay for things. Cash is paper money and coins. A debit card, tapping a card or phone, and paying online are other ways. They all use real money, even the ones where you never touch a coin.
Mia buys a book that costs $12. She taps her mom's phone on the reader at the store. No coins move and no bills change hands, but $12 still leaves her mom's bank account, the same as if she had paid with cash.
Keep card numbers and passwords private, like a secret you would not tell a stranger. If a message or a call asks for them out of nowhere, tell a grown-up before you answer.
Cash, cards, tapping, and paying online all spend real money, so keep your numbers and passwords private.
Which of these is a way people can pay for something?