eSIM, short for embedded SIM, is a type of SIM card that is embedded directly into a device, such as a smartphone, tablet, or smartwatch, rather than being a removable physical card.
Unlike traditional SIM cards that store user data on a physical card, eSIMs store user data and subscriber information electronically on the device's integrated circuit. This means that users do not need to physically swap out SIM cards when switching carriers or using multiple devices.