In Star Trek, a holodeck creates interactive simulated environments aboard a starship.
A holodeck combines holographic projections, force fields, replicated objects, and computer-controlled scenarios to produce an immersive environment. Users can walk through landscapes, interact with characters, and experience simulated physical objects. The technology is most closely associated with Star Trek: The Next Generation and later series.
Holodeck programs can recreate historical settings, alien environments, sporting activities, and fictional adventures. The computer normally controls the simulation, while safety protocols limit the danger of weapons and other hazards. Episodes frequently explore what happens when those safeguards fail.
A holodeck is not simply a screen or a virtual-reality headset. Its force-field and matter-generation systems allow participants to feel and manipulate parts of the environment. The related holosuite is a smaller or differently configured version, especially common on Deep Space Nine.