What's a "defragger"?

[arialdomartini]

Referring to the question

How would you design a "defragger" utility?

@monklof asked in #6

what is "defragger" ?

May be "File system fragmentation" is a better term?

[PlushyIndex]

A "defragger" is a computer tool that reorganizes fragmented files on the hard drive to make better use of disk space and enhance performance.

[arialdomartini]

@PlushyIndex yes, I think I should either rephrase that question or remove it.