<P> Attrib changes or views the attributes of one or more files . It defaults to displaying the attributes of all files in the current directory . The file attributes available include read - only, archive, system, and hidden attributes . The command has the capability to process whole folders and subfolders of files . </P> <P> These are commands to backup and restore files from an external disk . These appeared in version 2, and continued to PC DOS 5 and MS - DOS 6 (PC DOS 7 had a deversioned check). In DOS 6, these were replaced by commercial programs (CPBACKUP, MSBACKUP), which allowed files to be restored to different locations . </P> <P> An implementation of the BASIC programming language for PCs . Implementing BASIC in this way was very common in operating systems on 8 - and 16 - bit machines made in the 1980s . </P> <P> IBM computers had BASIC 1.1 in ROM, and IBM's versions of BASIC used code in this ROM - BASIC, which allowed for extra memory in the code area . BASICA last appeared in IBM PC DOS 5.02, and in OS / 2 (2.0 and later), the version had ROM - BASIC moved into the program code . </P>

What is command in dos explain the internal commands explain the external commands