lsblk major device number

When you enter:

lsblk

or better:

lsblk -o MAJ:MIN

you are getting some output related to major and minor numbers associated with the devices:

• the major number, which is on the left side of the colon – identifies the type of device driver associated with the device
• the minor number is used to differentiate among devices that are similar and share the same major number. For SCSI disks it helps to identify the different partitions of the disk

Below is a table for major numbers:

• 1 - RAM
• 2 - Floppy Disk Drive
• 3 - Hard Disk or CD-ROM
• 6 - Parallel printers
• 7 - loopback devices
• 8 - SCSI disk
• 14 - Sound
• 180 - USB
• 259 - NVMe disk

More information you can find on this document - devices.txt