Winston Smith is the central figure in 1984. Given the most common last name in England by Orwell, Winston Smith is an "everyman", a character who represents the average person.
A thirty-nine-year-old man who works in the Ministry of Truth, Winston Smith is fairly ordinary.
Winston's rebellion against the laws of his society are a rebellion of authentic humanity against the inhumanity and extreme constraints of the Big Brother regime. He is the protagonist of the novel and the source of all the novel's action.
Julia is an a-political, rather average woman. For Winston, Julia is an object of both temptation and danger as the two carry on an illegal liason. Julia is willing to break the laws and to disregard the validity of Big Brother's rule, but is not a revolutionary.
O'Brien and Big Brother are the novel's other major figures. O'Brien is a servant of the party and he draws Winston into a trap. O'Brien goes from being a potential friend for Winston to a definite enemy.
As a torturer, O’Brien reveals himself to be extremely intelligent and sophisticated.
It is O'Brien who articulates the designs and ambitions of Big Brother, telling Winston that he cannot defeat the overwhelming force of Big Brother. O'Brien ultimately breaks Winston and brainwashes him successfully, shaping Winston into a loyalist.