When we delete any folder or document it still store at recyclin bin

When a file is deleted, only the reference to the file on the HDD is wiped. The file physically continues to be where it was until that location on the HDD is re-written by some other information. Recovery software can directly access all the sectors on the HDD and retrive the deleted file provided it's not rewritten.

Recycle Bin is a safety mechanism provided by Windows that safeguards people from actually deleting the file they did not want to delete. It's like a 'second chance'.

Your system maintains a reference/pointer to every file you have in your HDD. When you delete it, the pointer gets shifted to recycle bin, you can recover that file, but if you permanently delete it, then the pointer is scrapped off.

But the file is still there in HDD. You can't access it because the pointer/reference has been lost.

Depending on the recovery software, you can get your file back in which best case is around 200 re-writes. (which is almost near to impossible in most cases). Although, you have 30-40% chances to get back your file if it's sector (where the file contains) is re-written 5-6 times.


PRIVACY/SECURITY TIP : It's recommended that you don't throw your old hard disks right away, as it may contain sensitive information which may be mis-used in any manner. It's advised to have some software and you re-write your disk more than 200 times . Of course it would take time, but at least you're safe !