There are a few types of block storage types in Linux.
- SCSI Disk - /dev/sd*
- MMC - /dev/mmc*
- UFS - /dev/ufs*
- NVMe - /dev/nvme*
- MTD - /dev/mtd*
SCSI Disk
- Spinning Hard Drives - single continuous sector-addressable block store
- SATA SSD - single continuous sector-addressable block store
MMC
- SD/MicroSD cards - single continuous sector-addressable block store
- eMMC modules - hardware partitioned sector-addressable block store
UFS
NVMe
- SSD
- SD Express
- CFExpress
MTD
- NAND - large RAW block-based store usually used for cheap devices
- NOR - small byte-addressable block store usually used for firmware