IoT SIM cards, aka M2M SIM cards (machine-to-machine), are used in connected devices in large IoT systems that work together from different places worldwide. They connect to mobile networks of all kinds, from 2G to 5G, across different carriers, without changing the SIM cards for different regions and countries.
Another term used interchangeably with the Internet of Things SIM is UICC (Universal Integrated Circuit Cards). They possess an international identification number that works for a particular device anywhere in the world. The UICC cards carry credentials and security keys that identify the cellular subscription.
IoT SIM cards are designed to work worldwide: their data plans cover dozens if not hundreds of carriers and networks around the world, so your devices can stay connected regardless of location
This type of card can store multiple IMSIs on a single profile, giving you access to dozens or hundreds of networks worldwide. This allows you to connect your IoT devices regardless of location and choose from multiple networks to get the best coverage and efficiency.
The IoT data plans are often standardized, so you pay a fixed amount no matter what network you’re using.
This type of SIM card is often used in IIoT. Explore what that is - https://www.mobindustry.net/blog/iot-sim-cards-technology-overview-and-use-cases/