CADD PRIMER is a beginner's reference book on computer aided design and drafting (CADD and CAD). CAD is a computer graphics software that is commonly used to make architectural and engineering drawings. This book describes the general principles of working with CAD that can be applied to all the leading CAD programs. A major portion of this book is FREE. You can download more than 70 pages of useful information that describe CAD terms, principles and applications.