Subscriber Identity Module or a SIM is a power free storage device which securely stores the service-subscriber key which used by the mobile networks to identify a subscriber on mobile telephony devices.
WiFi, Speed dialing, Bada, ARPU, WLL, Apps, Bluetooth, Roaming, VAS, Proximity sensor, Capacitive touch screen, EVDO, A2DP, Accelerometer, RFID, HSPA+, AGPS, Caller ID, Post paid, Rev B, iOS, Edge, Silient mode, Fuel cell, GSMA