A Directory is a logical section of a partition used to hold files. A directory is allowed to contain a directory. the CD command can be used to move up into a directory, move back into the parent directory, move all the way back to the root (/ in unix, C:\\ in dos) or move to any given directory name.
For example, in unix:
me@Wiki:~$ ls workreports games encyclopedia text.txt me@Wiki:~$ cd games me@Wiki:games$The user is now in the "Games" directory.
The same thing in DOS would look like this:
C:\\> dir workreportsNote that cd has different effects on different operating systems if given with no arguments. For example, if executed without arguments in DOS, the current working directory is printed. If executed without arguments in Unix, then the user is returned to the home directory. The effect of executing the cd command within a script or batch file also varies. In DOS, the caller's current directory can be directly altered by the batch file's use of this command. In Unix the caller's current directory is not altered by the script's invocation of the cd command.
Wed Oct 9th 9:01 games Tue Oct 8th 14:32 encyclopedia Mon Oct 1st 10:05 text txt 1903 Thu Oct10th 12:43 C:\\> cd games C:\\games\\>