Many of the technological advances predicted in Star Trek’s fictional universe have become reality, such as the mobile communicator and hand-held tablet computers.
Others, such as tractor beams and warp drives, are still a work in progress. But what of the Holodeck?
The Holodeck first appeared in The Practical Joker, a 1974 episode of the Star Trek animated series. It was depicted as a recreation room containing a simulated, alternative version of reality. It featured heavily in The Next Generation series and in the 1996 film First Contact.
,
Source: The Conversation