http://www.computerhope.com/msdos.htm
Microsoft has slowly been trying to get rid of DOS, but it is just to handy...I routinely use it at work....for networking purposes, as well as "batch" files for login scripts in a Microsoft enviroment. If you learn Linux, it is like DOS on steriods. You can preform much more complex solutions that you can only dream about in Microsoft (or pay thousands of dollars to purchase a product that will do the same thing).