What does disk defragmentation do?
Your hard drive is split up like a pie into sectors. When you save something, the data is written to these sectors and your hard drive knows right where to look when you go to access that data again. As you save more an more data, the sectors begin to fill up. The problem is, when you delete something – i.e. and old document you don’t need anymore – that data is erased from its spot in the sector, leaving a big empty hole. Then, when you go to save something new, your hard drive says “hey, theres some free space, lets use that up” and it places some of the data from your new file in that space, and saves the rest to a different spot. Then when you access that file, the computer reads the data in that section, and then has to go fine the rest in a different sector. When you defragment the hard drive, what happens is the little pieces of scattered data are effectively picked up and moved so that they sit right next to the other part of file they belong to. That way when you go to read th
