The PIN number is a 4-digit number that you must enter at the machine for each transaction. It is used to identify your account, since only you know this number. Keep this number carefully and secretly, and do not name it to anyone, as others can access your account.
If the card is lost, call the free number of your bank as soon as possible, which is specially designed to block cards. They can be found on your bank card, in the related documents or on the bank's website. After the blocking, no one can access your account.
For each card you receive from the bank, you will receive your own PIN number.