It doesn’t just defrag it optimizes files and their positions or location on the disk. If you do this before you load programs especially , it can be helpful. Your drive can access files in a more orderly fashion, which makes it faster.
Fragmentation happens when those files get split between blocks that are far away from each other. The hard drive then takes longer to read that file because the read head has to "visit" multiple spots on the platter. Defragmentation puts those blocks back in sequential order, so your drive head doesn't have to run around the entire platter to read a single file.
Fragmentation happens when those files get split between blocks that are far away from each other. The hard drive then takes longer to read that file because the read head has to "visit" multiple spots on the platter. Defragmentation puts those blocks back in sequential order, so your drive head doesn't have to run around the entire platter to read a single file.