Universal integrated circuit card
The universal integrated circuit card (UICC) is the physical smart card (integrated circuit card) used in mobile terminals in 2G (GSM), 3G (UMTS), 4G (LTE), and 5G networks. The UICC ensures the integrity and security of all kinds of personal data, and it typically holds a few hundred kilobytes.
Source: Wikipedia — Universal integrated circuit card (CC BY-SA 4.0)