Command: move

Move: -m [src] [dest] [len]

Moves data from the source to the destination

hexed -m 100 200 20 file

Will move 32 bytes from 0x100 to 0x200 and move everything from 0x120 to 0x220 down by 32 bytes.

Move Overwrite: -mo [src] [dest] [len]

Moves the data from the source to the destination writing over the original data at the destination

hexed -mo 100 200 20 file

This will move 32 bytes from 0x100 to 0x200 but will insert zeroes into the file below the destination. This way the data will appear where you expect it to be after the move.