Why does deleted data stay on a HDD once written, waiting to be overwritten, as opposed to being removed when requesting deletion?

Question

Why does deleted data stay on a HDD once written, waiting to be overwritten, as opposed to being removed when requesting deletion?

In: 22

Answer 1

So data is written to a hard drive, but programs need a way to find that data afterward. So it’s given a signpost pointing to the location on the hard drive where it can find that data. When you delete something, it’s not actually deleted, but rather the signpost is. This lets the drive manager know that it can put up a new signpost to write new data. But that binary data – the zeroes and ones – remain where they are until they are overwritten by new zeroes and ones. This is more efficient because data typically does not need to be destroyed when no longer needed.

Manually deleting a hard drive, on the other hand, involves an extremely time-consuming process of changing *all* of the zeroes and ones in every space of the hard drive.