eSIM is not a type of SIM but rather a concept that refers to a SIM that can load new carrier profiles digitally, over the air. eSIMs are standardized by the GSMA and come in two architectures: Consumer Profiles for consumer devices and M2M Profiles for IoT applications. eSIM makes sense for IoT deployments due to its ability to decouple hardware from network decisions, allowing for global deployments with the same hardware and flexible carrier selection. The concept of eSIM is often confused with embedded SIMs, which are a type of SIM that is soldered directly onto a circuit board. eSIM has gained popularity in consumer devices such as iPhones and is now being adopted by IoT applications due to its benefits in terms of space constraints, remote installation, and long-lived deployments.