The Matrix trilogy takes place in two opposing settings: there’s the “real world” in the distant future where humans fight for survival, and the simulated reality of the Matrix, where most people remain trapped in a simulated version of the early 2000s. Neo’s world—when he’s still under the influence of the machines and hasn’t taken the “red pill” that wakes him up—resembles an early 21st-century city with towering skyscrapers and sterile offices. It constantly rains and the lighting is always a sickly greenish-gray. The design of Neo’s world is full of order and repetition, which makes his job as an illegal hacker seem even more dangerous and subversive. People like Neo living within the simulation exist without questioning their surroundings because the illusion of reality created by the machines is perfect. The characters are unaware that the world they see is a facade until Neo “wakes up” after meeting with Morpheus. 

The Matrix itself functions like a complex computer system. Humans with the ability to hack into it can fight the machines from within. They can also use their programming skills to “download” any number of weapons, vehicles, and years' worth of martial arts training in seconds. This allows Neo, Trinity, and Morpheus to become incredibly skilled hand-to-hand fighters. When a human is born into one of the machine farms as a “battery,” they are equipped with a series of “plug” sites all over their body, including a central plug which connects their brain and nervous system to the Matrix directly through the base of their skull. These “plugs” enable Matrix-born humans to re-enter the Matrix at will through human-controlled points. However, they must use special exit points—usually ringing telephones—created by real-world human hackers to get out of the simulation and back to the real world. It’s often a life-or-death scramble to get to these exit points, as humans who die in the Matrix immediately die in the real world. Humans who have learned how the Matrix works can sometimes perform supernatural athletic feats by manipulating its programming; for example, Morpheus can leap enormous distances and move with incredible speed.  

Being in the Matrix is extremely dangerous for humans, as their machine enemies can detect their presence and send “agents” to eliminate them. Before Neo, no human had ever been able to win a fight against an agent. Neo, however, is eventually able to bend the rules of the Matrix to his will, allowing him to “move like one of them” and eventually defeat them. There are also lots of zones in the Matrix’s program which aren’t a part of the machines’ official regime. In these spaces, special programs like The Oracle, the Keymaker, the Architect, and the Merovingian rule their own small domains and work for their own obscure purposes. 

The “real world” that Neo awakens in could not be more different from the digital reality the machines have constructed to enslave humanity. In the far future, Earth’s atmosphere is almost unbreathable because of humanity’s desperate attempts to fight the machines. In an effort to stop the artificial intelligence they created from using the sun as a source of power, humans changed the weather so that thick black clouds would permanently cover the sky. The machines turned to using humans as a power source instead. They destroyed all of the human dwellings above ground, replacing them with colossal, plant-like structures where human beings are farmed as living batteries. In the brief vision Morpheus shows Neo of the “real world” of the future,  twisted metal and collapsed buildings clutter the smoking, desolate landscape. The black skies are patrolled by vicious and ever-watchful machines guarding and “farming” the unconscious humans.  

Because the surface of the planet has been destroyed, Zion, the last human city, lies underground in a vast cavern. It’s a massive stronghold which is kept at a tropical temperature by the Earth’s molten core. In order to build Zion, humans carved into the rock of a pre-existing cave and made it habitable by filling it with machinery and life-support systems. In Zion, life is hard: humans wear ripped and ragged clothing and crowd into small, spartan living spaces. Resources are very scarce. For the most part, people live on a porridge-like gruel to survive. Death is common and violent, whether it’s a “real world” death where machines physically harm the humans or a “Matrix” death, where they “die” in the simulation and their brains collapse around the plugs connecting them to the illusion.