Replace or overlay

Virtual reality (VR) uses a headset to present a computer-made environment instead of the room around the user. It is useful for practice: a technician can rehearse a rare failure, learn the order of a procedure, or make mistakes without standing beside a live machine.

Augmented reality (AR) keeps the real room in view and adds digital material such as a checklist, an arrow, a diagram, or a remote expert’s annotation. AR may use a tablet, phone, or see-through display; it is not defined by a particular headset.

For a live repair, AR can be useful only when the information is accurate, does not cover a hazard, and does not distract the worker. A voice call, a paper procedure, or a tablet may be safer than a wearable display for many tasks.

Use VR for rehearsal when replacing the room is an advantage. Use AR only where adding information to the real room improves the job without reducing situational awareness.