Its main thing is taking a system that’s just powered on, and giving it an operating system. Said system can then run HPC jobs (or shell sessions, or web sites, or data-transfer); until it’s rebooted, and the cycle begins again.

I don’t know how well it would work in IoT: The device needs to PXE-boot, which requires support from the DHCP server and the hardware boot environment (UEFI).