Thread: Does MOBILE PHONES have any kind of retrieving system??

I have just got this news and I wish to know how muich is it true.
The news says that if we have saved a video clip in a mobile phone then even after deleting it the information can be retrieved by some software. But how is that possible?? Is the information true?Then the memory space needed should be high. Kindly provide as much detail as possible. I am a novice and does not understand much about electronics but I have a learning habbit. I wish to get some positive reply.
THANK YOU.

Computer memory usually maintains an "index" of where all the data for each file is. When you delete a file, the device (your computer, phone, or whatever) will simply delete the entry for the file in the index and mark the deleted file's location as available for new data. It doesn't actually go through and erase all the data from the file, it just marks the space as available for new data - but the old data will still be there until new data is written over it.

So if you delete a file, the data is usually still there and can be retrieved by someone with the proper tools. If you erase a file and them fill up your memory with new data, the old data will be gone because it will have been overwritten by the new data.

Can I get some more information? Does the memory of mobiles and computer work in the same way? Can there be some space in the memory which cannot be used but kept for security purpose such as retrieving. When some information is written on the disc what actually happens and how it can be erased completely? If the deleted message still stays then why cannot we avail it in normal process?
I will be thankful if I get the chance to know this and I wish to know more let me know how can that be possible?