Wirebook › Glossary › File system
What is a file system?
In one sentence: The part of a computer that keeps the list of which blocks on a disk belong to which file.
A little more
A disk is just millions of numbered blocks. The file system is the index that says which blocks belong to which file, what each file is called, and which blocks are free. When you delete a file, the file system usually only crosses it off this index and marks its blocks as free.
That's why recovery programs can sometimes bring files back: the data is still sitting in the blocks until something new is saved over it.
It's a bit like… The contents page of a scrapbook: tear out the line that says where a photo is, and the photo is still glued inside until you stick something over it.
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