When the Matrix was first built, there was a man born inside who had the ability to change whatever he wanted, to remake the Matrix as he saw fit. It was he who freed the first of us, taught us the truth - As long as the Matrix exists, the human race will never be free. After he died, the Oracle prophesied his return and that his coming would hail the destruction of the Matrix, end the war, bring freedom to our people. That is why there are those who have spent our entire lives searching the Matrix looking for him.”
― Morpheus telling Neo of The Fifth One.[src]
The One, also known as the Prime Program, is a systemic feature of the Matrix wherein a special code is carried by a randomly selected human being. This person is then gifted vast superhuman abilities as an avatar within the Matrix, which sometimes manifests as extraordinary powers in the real world. The special code has the function to collectively attach, to the person that carries it, all of the anomalies which emanate from the few humans who continue to reject the Matrix. This essentially makes The One an "Integral Anomaly" or the SUM of all anomalies.
The mechanisms by which The One appears are rather simple and arranged in the Prime Program process: when the anomalies in the Matrix reach a certain threshold and begin to pose serious problems, a random human is selected by the machines to be born with a special code (the Integral Anomaly) that, as said before, ties and attaches all of the anomalies within the Matrix to the programming of this human. The Oracle, who is aware of The One's existence and purpose because it is her duty to guide humanity to find The One, will enlighten him to his true nature and lead him towards the Source where he fulfills his purpose of reinserting the Prime Program and resetting the Matrix. She does this by predicting the return of The One to the people of Zion to aid them in freeing humanity from the Machines' grip. The Architect, as creator of the Matrix, is also well aware of The One's existence and purpose, referring to The One as an "eventuality".
Essentially, the purpose of The One is to ensure the stability of the Matrix through containing the anomalies in one individual rather than letting them spread throughout the system.
Neo initially has doubts that he is actually The One when he first meets the Oracle, who appears as an old woman. She claims that Neo has "the gift", but that he appears to be waiting for something. She makes a prediction: Neo will soon need to choose to save the life of Morpheus, or his own; in any case, one of them will die (this is the first of three paths that the Oracle defines for Neo).
Neo's true nature as The One manifests after he is shot and apparently killed by Agent Smith while trying to escape the Matrix after rescuing Morpheus from interrogation by the Agents. After a confession and a kiss from Trinity, Neo reawakens in the Matrix, his powers enabled, and easily defeats the agents. Neo attacks Agent Smith, apparently destroying him from within. With Neo now having accepted his true nature, The Oracle proceeds with the next phase of her duty; she informs Neo that saving humanity as The One entails reaching the Source, which is the center of programming power for the Machines and where the Matrix receives its programming.
Your life is the sum of a remainder of an unbalanced equation inherent to the programming of the Matrix. You are the eventuality of an anomaly, which despite my sincerest efforts I have been unable to eliminate from what is otherwise a harmony of mathematical precision.”
― The Architect to Neo during their only encounter.[src]
During his meeting with the Architect, Neo learns a surprising truth about the Matrix. The Matrix is much older than the humans of Zion think. The Architect explains that, in addition to two unstable versions of the Matrix, there have been five iterations, or cycles, of the Matrix. In each stable iteration, an incarnation of The One has appeared. Neo is The Sixth One to appear in the sixth Matrix iteration in which the trilogy takes place.
In each iteration, The One is guided by the Oracle and then the Keymaker to a holding room of sorts where The One gains an audience with the Architect. The Architect explains the origin and history of The One to them as well as their purpose, after which he presents The One a choice: enter the door leading to the Source to reload the Matrix by reinserting the Prime Program, or return to the Matrix.
The One is subtly blackmailed by the Architect to enter the Source door by being informed that Zion is going to be destroyed, as happens approximately every 100 years, and therefore, if The One enters the Source door, they may pick twenty-three humans from within the Matrix to rebuild and repopulate Zion, thus saving humanity from extinction. If The One fails to enter the door to the Source, the Architect warns that the humans inside the Matrix will die when the Matrix destabilises and, alongside the destruction of Zion, will effectively render the entire human race extinct.
Neo, as with his predecessors, discovers that the Oracle's prophecy is a fabrication: a form of control by the Machines in order to steer The One to the Source (or, in the case of the Architect, a representative of the Source) in order for him to procure the Prime Program and reboot the Matrix to stabilise it at 100% perfection. Neo then deduces one of two things from this discovery: either no one told him the truth of The One's and humanity's fate, or nobody knows, because The One never returns to inform humanity of the truth of the destruction and rebuilding cycle every century.
However, the Oracle during Neo's iteration as The One has decided to end the cycle. She does this by subtly altering The One's pre-conditioned attachment to humanity, necessary for the "Messiah" purpose, by focusing this attachment on a particular individual instead, with the goal of ensuring The One physically travels to the Source and meets with the Machines personally to foster peace.
The Architect, upon explaining Neo's background and purpose as The One, also acknowledges the altered attachment of The One to humanity by revealing to Neo that Trinity entered the Matrix to ensure he would meet the Architect, despite Neo requesting her not to in order to try and save her from death as he had foreseen, and comments on how "interesting" it is to watch Neo's reaction.
When Neo chooses to rescue Trinity rather than humanity in general, the Architect, as representative of the Machines, shows a hint of desperation over the possible failure of the plan to reset and stabilize the Matrix. He then reattempts to convince Neo to choose the Source door. However, Neo refuses and he proceeds to rescue Trinity.
After Neo is rescued from Mobil Avenue station, he meets once more with the Oracle, who states Neo must still reach the Source - not the Architect, but the Machine City itself, where "the path of The One ends".
Neo succeeds in reaching the Machine City and meets with the leader of the Machines, the Deus Ex Machina. He argues that Smith, who has completely taken over the Matrix by then, will eventually cause the Matrix to crash. This would kill all of humanity and would thereby deprive the Machines of their power source, wiping out both species from existence. He then states that he can destroy Smith and save both species, and all he wants in exchange is peace between the two races.
The Deus Ex Machina agrees to the terms and plugs Neo into the Matrix to fight Smith. With his new powers gained from taking over the Oracle, Smith appears to be stronger than Neo and he manages to seemingly defeat him, but while he gloats over his supposed victory, he repeats the Oracle's words, "Everything that has a beginning, has an end, Neo", a statement that makes Neo realise that he had been going about Smith's defeat all wrong and that his own defeat is actually the way to defeat Smith, his opposite, and he allows himself to be copied over by Smith.
This action gives the Machines an opportunity to destroy Smith through direct access to him via the new Neo-Smith clone, a chance the Deus Ex Machina does not hesitate to take by sending a power surge through Neo's body that destroys the Neo-Smith clone as well as all the other Smith clones, including the Oracle clone.
After Neo sacrifices himself and Smith is defeated, the Machines uphold the terms of the truce that Neo proposes, and the Machine War ends, with Zion saved from the brink of destruction, and the Matrix successfully reloaded, thus ensuring survival of both humanity and the Machines.
By The Matrix Online, Neo is the last One and the Path of the One is complete. It is also revealed that the Machines select and breed each One.
The One is given special abilities by the Machines in order to enhance the idea of them being a "Saviour" to mankind so that they themselves will then believe it is their duty to save humanity. Some of these abilities are:
- Superhuman Strength: The One has superhuman strength far beyond that of normal Redpills. Neo showed this ability by pulling a pole out of solid concrete with ease. Furthermore, The One's strength is powerful enough to overwhelm upgraded Agents, despite the fact that upgraded Agents are created specifically to deal with The One.
- Superhuman Speed: The One can move at unmatched superhuman speeds. This can either be in flight or even during normal action, such as during a fight. Neo displayed this ability when he left the Architect's room. He flew across Mega City fast enough to catch Trinity as she fell, yet it was evident that he was a long distance away when she began to fall. He also displayed this ability during the fight with the Smith clones and the Merovingian's henchmen, where he fought several opponents at once with ease. Even before awakening as the One, Neo also proceeded to to dodge all but two bullets fired from Agent Jones' gun, with Trinity even being surprised by his dodging them like an agent.
- Superhuman Stamina: The One can exert themselves for extended periods without tiring at all far more than anyone else within the Matrix can. Neo displayed this ability by being able to hold a fight against several Smith clones for a long time without tiring, retreating only because he was outnumbered beyond what he could fight off. However, even this ability had its limits, as Neo ended up completely exhausted after a period of fighting Oracle-Smith.
- Superhuman Durability: The One can handle physical damage that would kill a normal Redpill. Neo demonstrated this ability by stopping a sword strike with a hand, suffering only a small cut in the process. He also survived being slammed into the ground from a high altitude by Smith, an action which a normal Redpill would not have survived. Even before awakening as the One, Neo showed at least some degree of superhuman durability, as he continued to keep on fighting even when suffering severe blows from Smith that were potent enough to force him him vomit up blood, as well as narrowly survive lightning-fast and repeated punches late into the battle, both of which would have killed an ordinary man.
- Superhuman Reflexes: The One was capable of engaging in reflexive maneuvers that most Redpills were incapable of doing. This was implied during the late stages of the Subway Fight where Neo managed to defy physics by launching himself to the roof of a subway tunnel in order to stun Agent Smith (who had pinned him down at that time) long enough to break free from his grip and then escaped, prior to his formally awakening as The One.
- Inner Sight: The One has a kind of "inner sight", which gives them the ability to see the Matrix in its true form, that of green, luminous lines of code, enabling them to see things others would not ordinarily see, such as hidden explosives. This also allowed The One to sense hidden ambushes well before they occur. This was best demonstrated during the Crisis Meeting, where Neo abruptly left the meeting due to sensing an arriving presence (heavily implied to be Smith), as well as him sensing Agents Thompson, Jackson, and Johnson just outside the door and barely warning Corrupt and Wyrm of their arrival and ordering for an end to the meeting as a result just before they kicked down the door.
- Reality-Warping: The One has the ability to bend the physics of the Matrix, allowing them certain abilities such as flight, telekinesis and healing abilities. Neo demonstrates these abilities by stopping bullets in mid-air as well as when he drew Sais to him while fighting the Merovingian's henchmen. The One can even destroy Agents as Neo did to Agent Smith in The Matrix, where he destroyed Smith's program from within him. It is unclear if Neo's predecessors were able to do this as it ultimately resulted in Neo imprinting onto Smith which allowed him to grow in strength and ability as well as become an exiled program, no longer controlled by the Machines. It even allowed Smith to leave the Matrix and take over a human in the real world, similar to how Neo's abilities were able to extend to the real world and destroy Sentinels. Neo also displayed the ability to heal other people in the Matrix by removing a bullet out of Trinity's heart and also starting her heart again after it stopped beating with his hand inside her. The stopping bullets portion of reality-warping was apparently well known to Morpheus, as when mentoring Neo about always being wary of Bluepills within the system due to them potentially becoming Agents, he mentioned that once Neo awakens as The One, not only would he be able to dodge bullets like Agents, but he would not even need to dodge bullets at all.
After Neo visits the Architect, he appears to gain more abilities such as being able to seek out and enter other Matrix-like worlds without being jacked in e.g. Mobil Avenue. He also demonstrates an enhanced "inner sight" that extends to the Real World, allowing him to see Machines, Machine-built landscapes and other entities endowed or empowered with Machine programming in a yellow, luminous light. He displays this ability after being blinded by Bane.
- Morpheus, in his speech to Zion prior to the Machine attack, tells the populace that the war has lasted nearly 100 years, suggesting that the Matrix has been reloaded once a century.