There are numerous identifiers for each device and network. A subscriber identity module (SIM) is an integrated circuit chip that stores the various identification numbers used by a mobile device. The SIM circuit is normally installed into a removable "SIM card".
These may be considered in much the same way as an IP number on a personal computer; they assist carriers in distinguishing one device from another and, therefore, also assist in a carrier's efforts to track and monitor each device. The following are definitions for a few of these identifiers. As a user, these will be most important to you in the event that your device is hacked; you will be able to understand these terms in your efforts to recover or repair your device.