Reducing size and size on the disk of a file or folder?

Question

I turned on File history for my laptop to save files to my external 4TB WD My Book drive but now I am running out of the storage space on the external drive and I checked that size and size on the disk of the file history folder on the external hard disk has a difference like 900 GB. How could I reduce the difference of size and size on disk?

Answer 1

Consider to add a tag to your post or to confirm that you are using Windows 10 to allow an edit to add such a tag. If this is not Windows 10, disregard this answer.

According to ghacks.net,

You have two main options to reduce the hard drive space that File History occupies at any given point in time:

Change the frequency in which copies are saved, and change 
the time period for keeping saved versions.
Clean up versions manually.

For the first option, consider this image, from the above linked site:

The second option that you have is to clean up File History versions. This deletes them from the hard drive and frees up space in the process.

Click on "clean up versions" on the advanced settings page to get started.