This lecture overviews Immersion in Virtual Reality  that has many applications in virtual presence and immersion. It covers the following topics in detail: Basic Concepts and Definitions. Presence (Prerequisites, Types, Measurements). Immersion (Requirements, Types, Measurement). VR Displays (Head-worn, Spatial, Hand-held). VR technologies Used. Applications: Immersive Videoconference, Immersive Learning Environments, Mixed-Reality Books, Immersive TV Entertainment.