Is the sim card a mobile phone card (what does it mean to apply for a sim card)

1. What is the slm card on the mobile phone?

2. Is the 2.sim card a mobile phone card?

3. What does it mean to enable the sim card?

4. What does 4.sim card mean?

1. Meaning of default slm card for mobile phone: Dual card can be set as default sim card, which can be used for making phone calls, texting and using traffic. If there is no other choice, the default card is used.

2. That is, one of the two cards in the mobile phone is set as the main card. Master card refers to the cost of using this master card by default for making phone calls, texting and surfing the Internet.