What is a SIM Card

Author: Fuzziimage // Category:
The SIM (Subscriber Identification Module or Subscriber Identity 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, letting the new phone receive all calls to the subscriber's number.


How does SIM cards work?

The SIM is inside each handset and functions as its digital brain. The authentication and encryption capabilities of the SIM prevent your phone from being stolen and your calls from being eavesdropped on. The SIM's digital memory, which stores information like your rate plan, phone number and service features, also allows you to easily personalize your service and contains user ID and billing information that can be switched between different phones. So, with your SIM card installed, you can make or receive calls personally even when you're using a borrowed phone. Upgrading your phone is as simple as slipping your SIM card into your new phone.