Can a mobile phone use two cards, one mobile and one Unicom?

Need to distinguish according to the type of mobile phone:

1. Dual-card dual standby mobile phone

This kind of mobile phone can use two cards.

Dual-card dual-standby mobile phone refers to a mobile phone, which can hold two SIM cards at the same time, and both cards are in standby state. Users can dial, answer and send and receive short messages at will without switching networks, and use 3G/4G to surf the Internet anytime and anywhere.

2. Dual-card single standby mobile phone

Some "dual standby" in the market are not real dual card dual standby. For example, some mobile phones can insert two cards, but only put two cards into the phone, which is just "dual card standby". It is necessary to switch the mobile phone to switch the A card to the B card (or switch from the B card to the A card), so as to realize the pseudo-dual-card standby.

SIM card is a subscriber identification module, also known as subscriber identification card and smart card. GSM digital mobile phone can only use this card.

Digital mobile phone customer information, encryption key and user phone book are stored on the computer chip, which can be used to authenticate the identity of GSM network customers and encrypt the voice information when customers talk.

SIM comes in three sizes:?

Standard card: the size is 25mm×15mm× 0.8mm;

MicroSim: commonly known as small card, with the size of12x15mm× 0.8mm;

Nano-size:12.3mm× 8.8mm× 0.7mm. 。

References:

SIM card-Baidu encyclopedia