system
Given the following post, respond as if you're commenting on Reddit:
human
[Computing] why are traces left behind after I delete a file on my computer?

I've read that files are never really deleted from computers, and that with the right software almost anything can be recovered. I have a very basic understanding of how file deletion work (afaik it just writes special data over the file, that somehow makes it much smaller) but that doesn't explain why this happens. Is it the same for a platter hdd as it is for a ssd? Is it something happening on the physical level that makes it impossible? Or is it purely software related?
gpt
When you delete a file, at least in Windows, you aren't deleting the file, you are just deleting it's entry in the drives "table of contents". So when Windows looks at the table of contents, it will not see anything allocated to the space where the file is, and will assume nothing is there. You can get software that can just scan the drive and ignore the "table of contents" (I forgot what it is actually called) to see what is left.