To extend this a little further, computers also don’t actually store books, they store blocks.

For example, you have a computer that can store 50 blocks of information. You store “Moby Dick”, taking up 20 blocks & “Tom Sawyer”, taking another 20 blocks.

Next you decide you don’t like “Moby Dick”, so you delete it. You also decide you want to store an ice cream menu, taking up just 1 block.

That menu will be stored based on where the computer thinks the block fits best. So you might have 20 blocks that still contain “Moby Dick”, or you might have only 19 blocks that contain most of “Moby Dick”, but it might be missing the beginning, middle or end.

If I were doing data recovery I might not be able to provide you with the complete “Moby Dick” story. I might only be able to give you part of it.

Looking into why blocks, let’s say you’re writing up the first draft of a book report, it might take up 4 blocks. Then later you edit, improve and add to that that book report, and now it takes 5 blocks. The computer took care of making space, even though your report got larger. It didn’t know if you were going to add 1 new block of information, or 1000 new blocks of information, it figured it out and did the rearranging for you.

However when it comes time for you to look at it, it automatically knows how to put it together. (And usually it does group things together if it can).

This is important to keep in mind when it comes to data recovery because the more you use your computer the more likely blocks are allocated and data gets moved around.

If you delete important photos, then spend the weekend surfing the Internet, those photos might be gone. Or if they are available, might only be partially available.