Money moves bank to bank in seconds, with no card number shared. You never enter your PIN to receive money — only to send it. Any request to do so is a scam.
The drawing that proves the sentence above. It is the same card that is in the book.
Think of it as
handing cash across the counter, but the counter is anywhere.
For example
You scan the shopkeeper's square and the money is in his bank before you have put the phone away. He never saw a card.
This is one card out of 275.
The hundred words you meet most are free — the whole set, animated, in one file that works with no internet.
Volume 1 has all 275 in fifteen chapters, with Staying Safe the largest chapter on purpose.