What is a SIM card?
The SIM (Subscriber Identity Module) card also known as a “smart chip” is basically the “brain” of the phone, providing cellular service as well as many other functions including call log, voice mail and SMS and GPRS (internet connection standards). SIM cards are the size of a credit card but they have a pop-out chip about the size of a postage stamp which fits into all modern GSM phones. The smart chip is embedded with circuitry and when inserted into a GSM mobile phone provides wireless phone service on a particular GSM network. SIM cards are usually available prepaid or on a contractual basis.
The SIM (Subscriber Information Module) card – a.k.a. “smart card” – holds all of a subscriber’s personal information and phone settings. In essence, it is the subscriber’s authorization to use the network. It also holds the phone number, personal security key and other data necessary for the handset to function. The card can be switched from phone to phone, making the new phone receive all calls to the subscriber’s number.
