The files are kept in a directory on each disk. the directory also contains information on the size of the files, and the dates they were created and updated.
When there is more than one user on you computer, or when you are working on several different projects, the number of files in the directory can become large and unwieldy. you may want your own files kept separate from a co-worker's or you may want to organize your programs into categories that are convenient for you.
In an office, you can separate files by futting them in different filing cabinets, in effect, creating different directories of information. MS-DOS allows you to Organize the files on your disks into directories. Directories are a way of dividing your files into convenient groups of files. this method of organizing your files is called a multilevel directory struture.
A multilevel directory structure can be though of as a tree structure. the root is the first level in the directory structure and it is automatically created when you format a disk.
The directory structure grows as you create new directories for groups of files, or for other people on the system. within each new directory, files can be added, or new subdirectories can be created.
