Surely they have heard many times the plbra defragment your hard disk but does not know that it is or that s referred to by that. Hard disk is where everything in the system is saved programs, files, videos, photos everything everything up the same system is saved there, everytime we create a file, eliminate one, install or uninstall something after these actions of there are small fragments and these occupy space on the hard drive of useless things llenandolo, not been account that sometimes only have a few opcas photos and music and your hard drive nearly full? because this is the reason an example with meal, when we eat a bread usually tend to fall crumbs onto the floor, suppose that our hard drive it is the floor, the floor is not swept long in this case not defragment, we continue eating bread and floor starts filling up with crumbs and we still sweep, will come a day that is full and not us or walk through of thethe same goes for the hard drive, it starts filling up since it becomes fragmented more every day and if not sweeping (defragment) is slow not only hara but that you no longer can put other things on the floor (hard disk)..