glossary our wiki for mobile communication

SIM Card

A SIM (Subscriber Identity Module) card is a small card that contains a mobile network subscriber’s account information. This allows the device using the card to attach to a mobile network.

There are 4 different sizes of SIM cards: full-size, mini-SIM, Micro-SIM and Nano-SIM. There are adapters available to use the smaller SIM cards in devices with larger SIM trays.