This lecture provides an introduction to the field of virtual reality (VR), focusing on the concepts and technologies that enable immersive real-time interaction. It covers essential topics such as human perception-action and the importance of ensuring users can react as if the virtual environment were real, even if it lacks realism. The course map outlines various key areas, including VR concepts, presence, 3D interaction, and haptic feedback. The grading scheme is detailed, highlighting components such as article study, group projects, and theoretical assessments. Students will engage in hands-on tutorials to develop practical skills in VR development using Unity 3D and the Oculus Quest. The lecture emphasizes the significance of programming knowledge, particularly in C#, and provides references for further reading. Overall, this lecture sets the foundation for understanding the immersive aspects of VR and prepares students for practical applications in the field.