What is a disk defragmenter? Does it help free up disk space?
Long answer : defragmentation is a process that reduces the amount of fragmentation in file systems. It does this by physically reorganizing the contents of the disk to store the pieces of each file close together and contiguously. It also attempts to create larger regions of free space using compaction to impede the return of fragmentation. Some defragmenters also try to keep smaller files within a single directory together, as they are often accessed in sequence. Sequential reading and writing data on a heavily fragmented file system is slowed down as the time needed for the disk heads to move between fragments and waiting for the disk platter to rotate into position is increased (see seek time and rotational delay). For many common operations, the performance bottleneck of the entire computer is the hard disk; thus the desire to process more efficiently encourages defragmentation. Operating system vendors often recommend periodic defragmentation to keep disk access speed from degrad
