There are two kinds of lock machines: one is with network lock; The other one has an ID activation lock. First of all, talk about network locks. Network locks are also bound to operators. That's a way to restrict users from choosing operators. Here is a warm reminder that the net lock does not refer to the lock.

Locking the phone can be understood as signing a mobile phone, which is a way to prevent your phone card from being broken by the operator (using a SIM card other than the operator) (but it can be unlocked, bypassing the operator's restrictions, so that the mobile phone that is still signing a contract can use other cards). So it is not difficult to understand why operators should set up network locks.

IPhone has a locked version, such as the American version of AT & amp； T, O2 In Britain, this kind of mobile phone can only be used by plugging in the SIM card of the corresponding operator, but it can't be used by plugging in other cards.

The extended information includes a locked iPhone, which generally refers to the contract machine of foreign operators. The hardware of mobile phone and lockless machine is the same in all aspects, except that it is bound to the operator's network (shielding the network of any other operator) and can only use American calling cards. If it is used in China, the card will have a signal, but the iPhone cannot be activated normally, so the lockable machine is realized in China.

Some locks even slogan "buy one get one free" abroad. As long as you use his calling card, you can buy it at a very low price. Compared with the lockless machine of the Bank of China, the newer the model, the larger the memory and the more obvious the price gap.

Reference materials; Baidu encyclopedia-apple xs