<Dd> In DR - DOS, help is a batch file that launches DR - DOS' reference, dosbook . </Dd> <Dd> Windows NT, all versions, uses DOS 5 style help, but versions before VISTA have also a Windows help file (NTCMDS. HLP or NTCMDS. INF) in a similar style to MS - DOS 6 . </Dd> <P> Evaluate the condition, and only if it is true, then it execute the remainder of the command line Otherwise, it skips the remainder of the line and continues with next command line . </P> <P> Used in Batch files . </P>

Explain any five internal and external dos commands