As a Mechanical Design Engineer once our design concept phase completes we move towards the detail engineering and drafting phase. The Design intent for functional requirement must be clearly communicated to the manufacturing shop for the product to get manufactured. The use of GD&T accurately controls the size, form, Orientation and Location of parts and hence results in manufacturing parts as desired. It also guides inspection, measurement teams. It also resolves the accountability for each department (Design, Manufacturing and Quality). This book provides a simplified and realistic approach to understand various concepts of Geometric Dimensioning and Tolerancing. The book is written based on the application of Geometric tolerance to the real world so emphasizes on most important concepts. Images Speak more than words and hence to the point explanation and lots of images and diagrams make it interesting to read. This book is designed to make a solid foundation for GD&T. This can help you to be Subject Matter Expert (SME), Implementing GD&T in your projects, passing certification exams, helping you in Job Interviews and leading you to the world of GD&T. This Book cover Virtual condition, Resultant condition, Inner Boundary and Outer boundary, FRTZF, PLTZF and Most confused term BONUS tolerance. This book shows the way for the selection of Datums, Details about Datum simulators, simultaneous requirements, RMB, LMB and MMB concepts and customized Datum references etc. This guides how to choose different Geometric Tolerances with functional examples. The book includes an explanation of the most used modifier for example. Application of modifier is explained with Geometric tolerance whenever comes in use. This book basically covers all concepts of ASME Y14.5 in a simplified manner. Reading this book and practising the concepts to your project will make a root to your subconscious.