Auto CAD is simply, design and drafting with the aid of a computer. Design is creating a real product from an idea. Drafting is the production of the drawings that are used to document a design. CAD was a revolutionary change in the engineering industry where draftsman, designers and engineering rolls begin to merge. CAD is mainly used for detailed engineering of 3Dmodels and 2Dmodels of physical components, but it is also used throughout the engineering process from conceptual design and layout of products, through strength and dynamic analysis of assemblies to design of manufacturing of methods of components. Auto CAD is used to design residential and commercial building projects. Civil engineers undertake large scale projects like building roads , bridges, industrial complexes and other infrastructural projects . CAD has become an important technology within the scope of computer aided technologies with benefits such as lower product development costs and a greatly shortened design cycle. CAD enables designers to layout and develop work on screen, print it out and save it for future editing, saving time on their drawings.