Samsung
Delete Photos or Videos in Gallery auf Samsung
Deleting photos or videos on a Samsung phone does not immediately erase them. Gallery moves selected files into a Trash folder first, so the storage space is not freed right away.
To delete one or more files, open Tap on Gallery ➔ Tap and hold a Photo/Video ➔ Select more Photos/Videos ➔ Tap on Delete ➔ Tap on Move to Trash. Holding down the first item switches Gallery into selection mode, so you can tap additional photos or videos before confirming the deletion in one step.
Why files still take up storage after deleting
The Trash folder acts as a safety net against accidental deletions. Files sit there for a limited time before Gallery removes them automatically, and only clearing the Trash frees up the storage immediately.
If you are deleting media because of low storage, check the Trash folder afterwards and empty it manually instead of waiting. If you only want to hide certain photos from the main view without deleting them, moving files to a private folder is the better option, since it keeps the originals untouched.