Please help explain about HarddiskVolumeShadowCopy

I have 2 files on my C: drive: C:HarddiskVolumeShadowCopy22 = 248 GB (266,455,478,272 bytes) C:HarddiskVolumeShadowCopy26 = 357 GB (384,213,041,152 bytes) for a total of 605 GB. Are these real files or do they represent links to files on my other drives? I have 4 other drives that hold 3+ TB.

The problem is that my C: drive is only 240 GB. Properties for C: are: Used space: 160.774.803.456 bytes 149 GB Free space: 48.940.392.448 bytes 45.5 GB Capacity: 209.715.195.904byles 195GB (28.29 GB Unallocated)

Can anyone explain, in laymen's terms, how Shadow Copy works?

Thanks.