Here's a short summary: Using "clean" in diskpart will remove all partition and volume information, but not erase data. Formatting, on the other hand, will erase all data on the disk. Think of "clean" as a "reset" and "format" as a "delete everything".
The "format" and "clean" commands in Diskpart are often confused with each other, but they serve different purposes. Diskpart is a command-line tool that allows users to manage disk partitions on Windows devices, including laptops and external storage devices. While both commands can be used to modify disk partitions, "format" is used to format a partition, whereas "clean" is used to remove data from a partition, making it ready for formatting. These commands can be used to extend, shrink, delete, and format partitions, but their specific functions are distinct.
The command "clean" refers to a process that completely erases a hard drive or SSD, deleting all partitions and wiping out all existing data, effectively deleting all existing data.
Format means to change the file system type of a partition or volume to NTFS, FAT32, exFAT, or another type, essentially repartitioning it.
Hence, they are completely different. However, I once used Diskpart commands, and I typed the wrong disk number. This command deleted all my data on another hard disk. I was heartbroken on that day.
To avoid data loss and accidents, I recommend using Qiling Disk Master, a reliable third-party tool that can wipe a hard drive before selling or format it to any file system, all without requiring any commands.