what is full form of sim

The full form of SIM is Subscriber Identity Module or Subscriber Identification Module. It is a portable chip and built-in circuit that securely stores the international mobile subscriber identity (IMSI) in a highly secure manner. SIM is a smart memory card that enables us to establish a phone call across the globe where the contact network of the user is constant. It is generally used on smartphone-operated and controlled GSM networks. The SIM card contains necessary information to and fro to your network and it also contains some of your personal data. A SIM also contains its unique serial number (ICCID), International Mobile Subscriber Identity (IMSI), security information, ciphering information, temporary information related to the local network, etc. . The first SIM card was made in 1991 by Devrient and Munich smart-card maker Giesecke.