SIM card (subscriber identity module) card is a programmable smart card in a mobile device that gives access to a network. It contains codes (such as the IMSI) to identify a subscriber to a digital mobile service and the details of the special services the subscriber has elected to use. A SIM card may be a removable plastic card with embedded memory and a processor chip or may be fixed within the mobile device.
This term is commonly used in software engineering, programming, scripting, application design, testing, and development lifecycle work.