To understand the concepts presented here, you will need to have studied Module 1-1, Nature and Properties of Light; Module 1-2, Light Sources and Safety; Module 1-3, Basic Geometrical Optics; and Module 1-4, Basic Physical Optics. In this module, a physical model will be developed so that all major features of basic holography can be explained through visualization and without the use of mathematics. Basic trigonometry will be helpful, but not required, for quantitative understanding.