The term Product realization is usually used to describe the physical realization of a product in the product development cycle. Therefore, the term may or may not include conceptualization and design phases. Considering that product realization means bringing a product to reality, it is important to study the concept of reality to understand the role of conceptualization, design, and manufacturing in product realization. In this paper, the concept of reality is expanded to include the perceptual and virtual realities as integral parts of the product realization process. This paper discusses the three phases of realization and their interactions. It also addresses the key roles of conceptualization, design and manufacturability in the realization process. To illustrate the concepts, presented in the paper, some examples are included.