How exactly does data recovery software work?

Instead of going into the low level detail, let me give you a short, high-level understanding of the basics behind the working of data recovery software. I am keeping it extremely simple, so as to make it easy to comprehend!

Let us use the analogy that your phone memory is a book, and the blocks of the phone memory are thepages of the book.  
Naturally, your data would be the text contained in the pages of the book.

Now consider a flag - 0 or 1 .  1means the page has occupied by some useful text. while 0 indicate the page of the book is empty or the text on it is useless. Makes sense, right?

Firstly, let us understand what happens when you delete a file. Does it vanish in thin air?

The answer is NO. What happened is that the pages of the book which contain the data are now marked with a "0", thus designating the space that the file is using as being available for future use when needed. The file never gets deleted, it's just no longer 'accessible'.


The deleted data is still in the memory of your phone, but you have indicated that you are not concerned about it , since you have deleted it. In course of time, the data in this space can be overwritten by new data, and thus compromising the original file that you have deleted.

So now, how does the recovery software work?
In layman's term, data recovery software scours the phone memory to look for the pages marked with 0 to locate any recoverable data, piecing it back together and providing it in a salvageable format.

While deleted files are inaccessible and are in danger of beingoverwritten, but they can often be recovered with professional data recovery tools.

But no data recovery software is perfect; if data has been partiallyoverwritten or otherwise compromised, the chances of any usable recovery are low, even with the best recovery software. But if it hasn’t been too long since you deleted the file, the chances of complete recovery are pretty good!