Agent Smith (later merely "Smith") is a fictional character featured in the Matrix film series and multimedia franchise, played by actor Hugo Weaving. The struggle between Neo and Smith becomes the main conflict underlying the events of The Matrix, which makes Smith the main antagonist of the series. Smith is an Agent, an AI program in the Matrix programmed to keep order within the system by terminating troublesome programs and human avatars which would otherwise bring instability to the simulated reality.
To this end, Smith possesses the ability to take control over the simulated body of any human wired into the Matrix. As an Agent, Smith possesses the ability to bend the rules of the Matrix (such as gravity and the limitations of the human body), giving him speed and strength beyond ordinary human capability. He and other Agents can dodge bullets flawlessly, punch through concrete with their bare hands, and jump impossible distances.
Agents also have the ability to communicate with each other instantaneously and perceive what other humans wired into the Matrix do, represented via their earpieces (when Agent Smith removes his earpiece during the first film, he is left unaware of the attack on his building). Smith's weapon of choice, as standard with all Agents within the Matrix, is the Desert Eagle, chambered with the high caliber .50 AE ammunition. The look and manner of Smith and his fellow Agents seem to be drawn from American pop culture.
One influence appears to be the popular image of federal law enforcement agents as ruthlessly efficient automata who carry out their duties with cold precision and General American accents.
Agent Smith: Did you know that the first Matrix was designed to be a perfect human world? Where none suffered, where everyone would be happy. It was a disaster. No one would accept the program... more
Agent Smith: Did you know that the first Matrix was designed to be a perfect human world? Where none suffered, where everyone would be happy. It was a disaster. No one would accept the program. Entire crops were lost. Some believed we lacked the programming language to describe your perfect world. But I believe that, as a species, human beings define their reality through suffering and misery. The perfect world was a dream that your primitive cerebrum kept trying to wake up from. Which is why the Matrix was redesigned to this: the peak of your civilization.