Windows 10: free space on ssd

My skill testing question is: why is it that in Explorer, I'll see the free space on my SSD down, let's say, about 30 Gigs. After a nice fresh reboot, that space is freed up.
It seems this is is not a continual thing but once in a bit, I'll notice the free space isn't what it was then as said, a reboot will rectify that. Any ideas as to why that is?
If any are not sure, just make something up because I'll believe just about anything. Thanks.

:)

 

SSD storage keeps filling up on its own

Hi Ash,

There's a possibility that the files are just hidden. As an initial troubleshooting, we suggest following the steps below on how to display hidden files that's eating space of your SSD:

• On the Search bar, type folder, and then select
  Show hidden files and folders from the search results.
• Under Advanced settings, select Show hidden files, folders, and drives,
  and then select OK.

Keep us in the loop with the result.

 

SSD space

I had to reset Windows 10 recently. the laptop worked wonderfully. The problem I have now is that the Dec Tuesday update did not work. Now windows modules installer continued to work and the SSD in one day filled almost to capacity. The SSD at the
start of the day showed 63GB of space used. At the end of the day, the total was 203GB used. I went to system restore and rolled back to the time before the update. I then had 75GB of space used but each time I checked, the space on the SSD was getting
smaller, about a GB every 20 minutes or so within 3 hours the used space went from 75gb to 102gb. I have since gone to the task manager and ended the process of Windows Modules Installer. The used space on the SSD is no longer getting larger, but how do I
regain the lost space on the SSD. THe SSD is a Samsung 250 EVO 850.

 

SSD space

Thank you all for your suggestions. What I ended up doing was to insert my USB drive with the Fall Creator's update and reinstall over windows keeping all of my settings. After that my SSD which is my C drive had
the total amount of space used down from 107GB of 250 to 51.7GB. Plus the December update that was causing all my problems and not installing, was installed.