Windows Shadow Copies
Most recent versions of Windows both automatically create shadow copies of the data on the PC's hard drive and allow the user to create a new one that will be saved.
The Windows 7 operating system on my home PC contains copies which were created yesterday, a week ago, and also a month ago. It's possible to review these versions by going into Windows Explorer, and selecting a drive letter. Right click and select Properties. Just click on the 'Previous Versions' tab and you'll see the option to open and browse in the shadow copies. Apparently the ability to browse through these shadow copies is available in Windows 7 and Windows 10, but not Windows 8.
If you want to create a shadow copy, go to Control Panel . . . System and Security . . . System . . . System Protection, and select 'Create'.
Both Sharepoint and SQL Server make use of volume shadowing.
Knowing the basics of 'Windows Volume Snap Service' is essential for anyone performing data collection.