Different security passwors present in the mobile-pin code and puk code

You can use access password to prevent unauthorized use of your SIM card.

PIN code
PIN code is used to prevent illegal use of user’s SIM card. If your phone has enabled PIN code protection, it will prompt you for entering PIN code. If wrong PIN code is entered for three times, SIM card will be automatically locked. Now you will have to enter PUK code to unlock it. PIN code is related to SIM card instead of the phone, and can be obtained from your network operator.

PUK code
PUK code, referring to personal unlock code, is used to unlock SIM card that is locked because of wrong input of PIN code. If wrong input of PUK code amounts to ten times, the SIM card becomes invalid. The PUK code is provided by your network service provider.