By default, the MobileSync folder on the C drive is the iTunes backup location on Windows devices. If you want to change this default backup location, first, you have to move the backup folder from the C directory to another location and then create a Symbolic Link between the old backup location and the new backup location.
After creating a Symbolic Link, you will see that Windows has created a shortcut folder with the name Backup inside the MobileSync folder (the old backup location for iTunes). This shortcut folder points to the new backup location for iTunes.