Appendix D: XR Glossary of Terms

Appendix D

XR Glossary of Terms

This glossary defines key terms, concepts, and technologies used in Extended Reality (XR). It serves as a quick reference for revision, interviews, and practical understanding.

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D.1 CORE XR TERMS

Extended Reality (XR):
An umbrella term covering VR, AR, and MR technologies.

Virtual Reality (VR):
A fully immersive digital environment that replaces the real world.

Augmented Reality (AR):
Digital content overlaid on the real world.

Mixed Reality (MR):
A blend of real and virtual environments where digital objects interact with physical ones.

Spatial Computing:
Computing that understands and interacts with the physical space.

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D.2 HARDWARE-RELATED TERMS

Head-Mounted Display (HMD):
Wearable device that displays immersive visuals.

Inside-Out Tracking:
Tracking using onboard cameras.

Outside-In Tracking:
External sensors track user movement.

Field of View (FOV):
Extent of the visible virtual environment.

Refresh Rate:
Number of frames displayed per second (Hz).

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D.3 INTERACTION & UX TERMS

Haptics:
Technology that provides tactile feedback.

Gesture Recognition:
Detecting hand or body movements.

Eye Tracking:
Monitoring eye movement for interaction.

Locomotion:
Movement method within XR environments.

Cybersickness:
Motion sickness experienced in XR.

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D.4 SOFTWARE & DEVELOPMENT TERMS

Game Engine:
Software for creating interactive 3D experiences.

Unity:
Popular XR development engine.

Unreal Engine:
High-end graphics engine.

SDK (Software Development Kit):
Tools for building XR applications.

OpenXR:
Open standard for XR interoperability.

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D.5 AR-SPECIFIC TERMS

Marker-Based AR:
Uses visual markers for tracking.

Markerless AR:
Uses sensors and SLAM.

SLAM (Simultaneous Localization and Mapping):
Mapping the environment in real time.

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D.6 VR-SPECIFIC TERMS

Presence:
Sense of being inside a virtual environment.

Immersion:
Degree of engagement in XR.

Teleportation:
Instant movement in VR.

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D.7 MR-SPECIFIC TERMS

Spatial Mapping:
Understanding the physical environment.

Anchors:
Fixing virtual objects in real space.

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D.8 NETWORKING & COLLABORATION

Social VR:
Multi-user virtual environments.

Avatar:
Digital representation of a user.

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D.9 ETHICS & SAFETY TERMS

Digital Well-being:
Impact of XR on mental and physical health.

Privacy by Design:
Protecting user data by default.

Accessibility:
XR usability for people with disabilities.

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D.10 EMERGING & FUTURE TERMS

Metaverse:
Persistent shared virtual space.

Digital Twin:
Virtual replica of a physical object.

XR + AI:
Artificial intelligence integrated with XR.

Neural Interfaces:
Direct brain–computer interaction.

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D.11 SUMMARY

This glossary provides essential terminology needed to understand, discuss, and apply XR technologies confidently in academic, professional, and research environments.