In The Matrix (1999), the simulated world inhabited by humanity is called the Matrix.
The film reveals that most humans live inside a vast computer-generated simulation while their bodies are used as an energy source by intelligent machines. The simulation presents an artificial version of late-20th-century Earth, allowing the machines to conceal humanity’s real condition.
Neo, played by Keanu Reeves, learns about the Matrix from Morpheus and Trinity. After taking the red pill, he awakens outside the simulation and begins training to perceive and manipulate its artificial rules.
Zion is not the simulation; it is the underground human city. The Construct is a blank virtual training environment, while Machine City is the machines’ real-world metropolis. These related locations are sometimes confused because the film moves between several levels of reality.