Sometimes when you install a program or create a data file, the file ends up chopped up into chunks and stored in multiple locations on the disk. This is called
What makes this happen?
When you first install your operating system and programs on your hard disk, they are written to the disk, for the most part, in one contiguous block without any gaps. The exceptions are certain system files that must be stored in specific locations. Over
time, as you create and then delete documents or uninstall programs, once-filled locations are left empty and you end up with files dotted all over the disk.
Now, when Windows is writing a file to the disk, it looks for a suitable piece of free space in which to store it. What happens, then, when you copy a 40M database or audio file to the disk and the biggest slice of free space is only 30M? Or say you modify
an existing file, appending a whole bunch of data so the file now takes up more space on the disk. To accommodate the files, Windows writes the first part of the file in one section of the disk and then scouts around for other places to store the rest of the
file. The end result is that a single file may be stored in several chunks scattered about the disk.