What do you mean by locking and unlocking iphone? What are the built-in card stickers and three-in-one codes?

1, iPhone has the difference between locking and unlocking.

Lock-free version means that SIM cards that can be inserted into any operator can be used normally and are not restricted by operators. The lock-free version can upgrade the firmware at will, without considering the problem of signal cracking.

The lock version adds a network lock, which means the operator is bound. Such a mobile phone can only be used normally if the sim card provided by the operator is plugged in, and other cards cannot be used. For example, the US version of the mobile phone cannot use the SIM cards of Unicom and Telecom in China. If you want to use another SIM card, you must crack and unlock it.

What happens if you don't unlock it? For example, if the Japanese version of the lock machine is not unlocked, you can't make phone calls, send text messages, surf the Internet through wap, etc. Can only be used as iPod Touch.

2. Card Sticker: Card Sticker is an unlocking tool used by the mobile phone when the software cannot be unlocked, so that your mobile phone can make calls with a card other than the SIM card specified by the operator.

3. Three-in-one: Three-in-one refers to the serial number of the mobile phone, and the serial number printed on the phone body label is the same as the serial number on the phone packaging box. "Three codes in one" is one of the important standards of licensed mobile phones.