InDesign is a program that allows you to layout graphic elements on pages for print. One other very important feature of a page layout program, and InDesign’s other main purpose, is its output features. InDesign is built to play well not only with desktop printers, but with the high-end printing and plating systems of real-world print shops. In sum, Adobe InDesign is where printed pieces come together. In some special situations, such as long documents like books & other programs, for every project a designer runs across, Adobe InDesign is the program to set it up in.InDesign is used to create various things such as catalogs, ads, flyers, calendars, letterheads, business cards, etc.