If a file is deleted from Google Drive directly via the web or indirectly by deleting it from a sync’d folder on a computer then that file is moved into the Google ‘trash’ folder.
Cutting a sync’d file and pasting it outside the sync’d folder also puts the cut file into the Bin.
In theory, Google will delete it 30 days later.
In practice it doesn’t always.
This can lead to Drive filling up its available space and deleted confidential files lingering when they should have been confined to oblivion.
It’s good practice to occasionally clear out the Trash (or Bin as it’s called sometimes).
Go to: drive.google.com , scroll (if needs be) the left hand menu then into Bin or Trash.
You may also go directly to drive.google.com/drive/trash
Once there, click the dropdown beside “Bin” (or “Trash”) top centre and select “Empty Trash”.
Sometimes even this does not work – or does not take effect right away. If it doesn’t and your aim is to delete a particular file or folder then find that file or folder, right click and “delete forever”.