First, let’s kill the biggest myth:
In the golden era of Windows 95 and Windows XP, "defragmenting" was a sacred ritual. Users watched colorful blocks shuffle across their screens, believing (often correctly) that this process would breathe new life into their sluggish hard disk drives (HDDs).
On traditional PCs with spinning hard drives (HDDs), files become fragmented over time, forcing the drive head to jump around to read a single file. Defragmenting reorganizes these pieces into contiguous blocks to save time.