What is the meaning of dev/loop in fdisk -l

[amartyasinha918]

When I did fdisk -l, I found that there are some storage like dev/loop0, dev/loop1, …
I have no idea what they are and do they really exist on my physical drive.

Here is the output of fdisk -l. Can anyone tell me about it?

[amartya@amartya-hp ~]$ sudo fdisk -l
[sudo] password for amartya:
The backup GPT table is not on the end of the device.
Disk /dev/sda: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors
Disk model: TOSHIBA MQ04ABF1
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: 7F47AB37-AC21-4116-A895-BBA0EEDF0E57

Device Start End Sectors Size Type
/dev/sda1 2048 534527 532480 260M EFI System
/dev/sda2 534528 567295 32768 16M Microsoft reserved
/dev/sda3 567296 839593983 839026688 400.1G Microsoft basic data
/dev/sda4 839593984 1154267135 314673152 150G Microsoft basic data
/dev/sda5 1154267136 1364082687 209815552 100G Microsoft basic data
/dev/sda6 1364082688 1427757055 63674368 30.4G Microsoft basic data
/dev/sda7 1427757056 1469038591 41281536 19.7G Microsoft basic data
/dev/sda8 1469040640 1470918655 1878016 917M Windows recovery environment
/dev/sda9 1953288192 1953304575 16384 8M Microsoft basic data
/dev/sda10 1470918656 1953288191 482369536 230G Linux filesystem

Partition table entries are not in disk order.

Disk /dev/loop0: 207.02 MiB, 217079808 bytes, 423984 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop1: 207.02 MiB, 217079808 bytes, 423984 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop2: 55.45 MiB, 58142720 bytes, 113560 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop3: 55.42 MiB, 58114048 bytes, 113504 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop4: 231.28 MiB, 242515968 bytes, 473664 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop5: 99.15 MiB, 103964672 bytes, 203056 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop6: 9.08 MiB, 9523200 bytes, 18600 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop7: 179.57 MiB, 188289024 bytes, 367752 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop8: 66.03 MiB, 69238784 bytes, 135232 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop9: 32.27 MiB, 33841152 bytes, 66096 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop10: 968 KiB, 991232 bytes, 1936 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop11: 162.87 MiB, 170778624 bytes, 333552 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop12: 32.09 MiB, 33644544 bytes, 65712 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop13: 122.01 MiB, 127934464 bytes, 249872 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop14: 65.1 MiB, 68259840 bytes, 133320 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/loop15: 98.96 MiB, 103772160 bytes, 202680 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

[Wollie]

A loop device is a pseudo device (actually just a file) that acts as a block-based device. If you want to mount a file, you must first create a loop block device that is backed by the file.

Here is a more detailed explanation:

Loop device

[Strit]

In addition, Loop devices are often used by Snap packages.