A SIM card is a smart card inside a mobile phone which carries an identification number that is unique to the owner. It is made up of a silicon integrated circuit chip onto a plastic card. It stores personal data such as contact details and messages.
SIM is an acronym that stands for, Subscriber Identification Module. It was developed by Munich smart-card maker Giesecke and Devrient in 1991.
SIM cards store network-specific information used to authenticate and identify subscribers on the network. Most important is ICCID number. ICCID is the Integrated Circuit Card Identity. It is the 18 to 22-digit code that is printed on the back of your SIM. It can also be found on the plastic card where your SIM card is attached. Every ICCID number is unique and serves as an identifier for your SIM card.
International Mobile Subscriber Identity (IMSI) and authentication keys are very important in the manufacture of the SIM card.
Service dialling numbers (SDN), service provider name (SPN), and value-added service (VAS) are amongst the data the SIM card stores.
SIM cards are chips that hold information and allow you to connect with your network. This means you can make calls, send text messages and connect to mobile services like 3G, 4G, and 5G. You can decide to save messages and emails on them.
What happens if you take the SIM card out of your iPhone?
In the event that you take your SIM card from your iPhone, you cannot make or receive calls or send or receive text messages. You cannot connect to your network also.
Nonetheless, you can connect to WiFi and surf the internet without a SIM card.