...
There are many software tools for the retrieval of deleted files. Those tools, often referred to as "file recovery" software, are taking advantage of shortcomings in the "delete" command that we all use regularly to delete files. Actually, the "delete" operation only removes information from files , so they can't be found by the operating system. It can be easy to retrieve those files using aforementioned specialized file recovery software. In order to remove or shred files permanently from your system, you have to use a program that is capable of overwriting the file(s) with random series of binary data multiple times. This process is often called shredding.
...