Commonly Used DOS Commands (External)

Yesterday  I presented Commonly Used DOS Commands (Internal).So I will present the Commonly Used DOS Commands(External).We can't look down these commands because last time Window OS sunk in DOS Commands. We can kill VIRUS with commands.OK!! Let start!!
ATTRIB   -displays or changes a file's attributes
DEFRAG    -reorganizes the files on a disk to make them contiguous
DISKCOPY -make a copy of a complete disk
EDIT -invokes the text editor program
FORMAT- prepare a disk for receiving files
FORMAT/S-formats a disk as a system disk
MEM- displays information about a computer's memory, how memory is allocated, what memory areas are free, what programs currently loaded,etc.
SCANDISK -disk analysis and repair utility that checks and errors fices common disk and file
UNDELETE- will recover a deleted file
XCOPY- copies the contents of one disk to another disk