The software that controls computer's essential functions is called its operating system. While all other software programs are called as applications. They include word processing that which helps to write letters and for documents and multimedia that is the combination of video , music text, pictures and animation altogether. The designers of books, brochures, newsletter, magazines and newspaper arrangement of pictures and text on each page using software is called as desktop publishing. DTP also allows editors to correct text on screen. It is usually used for commercial printing or creates documents for desktop. Small business entrepreneurs, secretaries, individual consumers do desktop publishing for profit motive. Before the invention of DTP software, the tasks of such kind were performed manually by individual themselves.