What does sim card mean to write a card?

Writing a SIM card means storing user-related data.

The data stored on the SIM card includes:

1, fixed storage data. This kind of data is written by SIM card center before ME (mobile equipment) is sold, including international mobile subscriber identification number (IMSI), authentication key (KI) and so on.

2. Relevant business codes, such as personal identification number (PIN) and unlocking code (PUK).

2. Temporarily store data about the network. Such as location area identification code (LAI), mobile subscriber temporary identification code (TMSI), etc.

Extended data:

Capacity range of smart SIM card:

1, SIM card can store phone books and short messages with the following capacity:

2.8K card phone book capacity 20-40, 10- 15 SMS;

3. The phone book capacity of 16K card is 150-200, and the short message is15-40;

4.32K STK card's phone book capacity is130-150, and short messages15;

5. Please refer to the mobile phone display for the specific SIM card memory.

6. Card types (MINI-SIM, Micro-SIM, Nano-SIM) have nothing to do with card capacity.

Baidu encyclopedia -SIM card