Apple Computer appdata filling Win10 hard drive

My Win10 laptop is running very slowly due to the drive running programme files and software being almost full. When I use WinDirStat to see which files are consuming space I find the following:

Window (C): users; imarr; AppData; Roaming; Apple Computer; MobileSync; Backup; 356522e68437a8384e72705b564ec641f60e5a5b (and three other subfolders with similar obscure names)

The total space taken by these four folders is 22.7Gb.

Does anyone know what these folders are for, what generates them, and are they necessary? I have an iPhone 8 and iPad Air 4 which are synced to the laptop (iTunes, iCloud, contacts etc) so want to retain that facility but need to clean-up the laptop hard drive to free space and get it running faster (doing a disk clean up on the laptop does not clear any significant space).

Thanks in advance.