Winston Smith is the central character of 1984, but he is not presented as the hero of the novel. At the beginning of the book, Orwell is careful to present Winston in an unheroic light, and by the end of the book it is clear that Winston has not achieved the status of hero by his behaviour.
How does Orwell present Winston? Firstly, his appearance is against the traditionally heroic mode: he is 'a smallish, frail figure', with a varicose ulcer above his right ankle. he is physically unfit—he has to pause several times as he ascends the stairs, and has difficulty with the regulation Physical Jerks.
However, appearances can be deceptive, and the fact that a character is rather puny need not disqualify him from being classified as a 'hero' rather than a 'main character'. It is in Winston's actions that his importance lies.
His job is to overwrite the truth, to replace the history of what happened with a revised version. Winston enjoys his work and is good at it, yet at the same time he worries about the rewriting of history, and wants to know 'what really happened'. However, he does not seem to do anything as basically sensible as to keep a personal record of events. When he starts to write in his diary, his babbled outpouring is absurd, repellent, and rather contemptible. Also, for someone who makes his living by writing, it is pitifully poor stuff. However, the capitalised writing of 'DOWN WITH BIG BROTHER' is on a braver level, and hints, that he might, perhaps, have in him a measure of heroism. However, Orwell debunks this at once by the ludicrous contrast between Winston's fears and what actually happens: Winston is terrified that the Thought Police will come for him, now that he has indulged in such utterly forbidden ideas—but when there is a knock on the door, it is only his neighbour Mrs Parsons, with a plumbing difficulty.
The presentation of Winston as an unappealing and rather ineffectual man continues in his relations with women. There is a rather repellent account of his visit to a prole prostitute. The relationship with his wife appears to have no redeeming features (later in the book, Winston admits to an urge to murder her, but lacked the courage to carry it out). His attitude to Julia, before he learns that she loves him, is of violent loathing with unsettling sexual undertones'[ but when their relationship starts it is entirely because of her efforts. In some ways, Julia is actually more heroic than Winston—she is far more proactive than he. But Julia does not think about her situation in any depth, which Winston does.
Although Winston does think a great deal about his world and his personal situation, he is not necessarily very perceptive. In fact, he is naive in many ways. He is delighted to learn that Julia has slept with many other men, because "anything that hinted at corruption always filled him with a wild hope". More significantly, he eagerly swallows all the claptrap O'Brien feeds him about the mysterious 'Brotherhood', because he so very much wants it to be true. He accepts all the outrageous demands in the catechism from O'Brien without, apparently, giving a moment's thought to any of them. Later, when imprisoned, he puts an inordinate amount of faith in the idea that someone will convey to him a razor blade so that he can commit suicide—without for a moment noticing that he, Winston Smith, has no vital knowledge which only death could protect.
Winston does demonstrate some heroic qualities. One is, simply, that he remembers, in a world where he has to wonder whether he is the only person who can remember. He denies the faked truths of the present, and asserts the existence of the past—in his circumstances, this is heroic behaviour, even if Winston does not necessarily intend it to be such. In addition, he endures, for a long time, the sadistic and essentially pointless torture to which he is subjected. He understands that "To die hating them, that was freedom." But Winston's story does not end in this kind of victory. In fact he has not the strength to achieve this ambition, and at the end of the book has learned to love Big Brother.
Winston is clearly not presented as a 'hero', either through his own thoughts and behaviour, or through what happens to him. He is simply the main character of the book, from whose viewpoint the horrifying society and events are shown. Orwell takes care that his readers will not identify too closely with Winston, partly by showing us quite a lot that is repellent in Winston, but also by the careful distance maintained between the narrative and the character. Although we see the world from Winston's point of view, we are given his thoughts by the narrator, not directly by the character.
By seeing the society of 'IngSoc' via one particular character, it is easy for Orwell to present his many targets for bitter satire.
The most obvious target is totalitarianism. There are obvious references to Soviet Communism (Big Brother even looks like Stalin!), but naturally the totalitarian nature of Ingsoc is an exaggerated version. The surveillance devices are impossibly thorough given the technology Orwell shows in the book (though perhaps today's satellites could achieve it) and the impossibility of keeping track of everyone—but they certainly convey the sense of fear and oppression, and the lack of privacy, which such totalitarianism would impose. Ingsoc does not merely ignore the disparities between what it promises and what it delivers—it makes a point of them, noticeably in the names of the Ministries. Ingsoc's glorious leader is more than a man—Big Brother is to all intents and purposes immortal (and almost certainly not an individual with a human existence at all).
The satire of totalitarianism incorporates the attempts of English Socialism in Orwell's own time to impose its own required way of life; however, in a broader sense Orwell also satirises religion. The author quite probably saw religions as an attempt by one group to impose their will on others, in a very similar way to that in which communists (and fascists) operated. The concern to control thoughts as well as actions is very telling. O'Brien explicitly states that "God is power" and says "we are the priests of power". Big Brother is immortal, and the all-seeing eye of the television is a less benign version of the God who sees every sparrow fall, while the enemy Goldstein is an 'arch-heretic'. The concept of 'blackwhite', and the ability of loyal Party members to believe what they are told to believe rather than what they can see, feels like a swipe at the kind of faith that tends to require its followers to believe in contradictory ideas (like going to war in the name of the God of Love).
The use of language is an important aspect of the book, with Orwell going into considerable detail on the concept of Newspeak. The idea of the 'dictionary' which actually reduces the language in size is absurd—dictionaries cannot mandate the obsolescence of words—but Newspeak can be seen as the satirical exaggeration of the real-world tendency to use jargon to disguise rather than clarify the truth. When death is described as 'collateral damage' it loses quite a bit of its sting, and when excellence is described as 'doubleplusgood' it lacks something of its accustomed shine.
As a broadcaster during World War II, Orwell was all too familiar with the concepts of propaganda and censorship. The rewriting of history is, to some extent, familiar to any historian, as fashions in interpretation are always changing. Winston Smith is a cog in the machine which rewrites history for Oceania. He knows that this is done, and attempts to achieve some idea of the truth, investigating the absurd piece of 'history' about capitalists, which mixes a few simplistic truths with some quite ridiculous lies—factory owners having the 'droit de seigneur' over their workers, for instance. However, the exaggeration does reinforce the point. Today, there is some controversy over whether the Vikings should be portrayed as fierce invaders or mild-mannered farmers looking for new pastures.
The most exaggerated and dramatic instance of rewriting the past occurs during Hate Week: in the midst of a speech, the Great Enemy is changed from Eurasia to Eastasia, without explanation—and everybody instantly accepts the new truth. People are eager to find an explanation for the discrepancy between what they are being told and the evidence of the posters and banners around them (obviously, the agents of Goldstein have been at work). It seems likely that Orwell was also making a point about the way in which countries switch allegiances. During the War, Russia had first been at peace with Hitler's Germany, then fighting alongside the Allies. After the war, another switch saw the Soviets as the new Enemy.
These are the major targets for satire in 1984, but other matters are dealt with along the way.
Sexual repression is taken to extremes. Winston's wife can only bear to undergo intercourse as it is her duty to the Party. The young are encouraged to enrol in chastity leagues. (Not that child-rearing appears an enticing option, when children are encouraged to put the Party before their families, and are taught to be little thugs.) Perhaps this is an attack on the view of certain religions, especially Catholicism, that sex should be about procreation? Perhaps it simply exaggerates the prudish morality of the times, which was presumably getting back to 'normal' after the difficulties of wartime relationships, GI brides and so on. Winston regards sex as a political act, an assertion of freedom, in that it places the individual above society.
Other post-war aspects of society, such as rationing and shortages, are satirised with exaggeration, in the absurd statistics on production which are mentioned here and there. They sound very much like the output of the USSR in later years! Bureaucracy, too, is everywhere.
Lastly, there are those novel-writing machines and the equivalent churners-out of popular music. Orwell was clearly mocking the brainlessness of much 'pap' literature and 'genre' fiction (and the people who read it) and its musical equivalent.
1984 is not a novel which really needs a 'hero', because if one person were able to assert himself against the society portrayed in the novel, there would be a message of hope—and this is not the case. The novel is a dystopia, and a warning against many things which are satirised in its pages, and is all the more powerful because its central character cannot stand against the world in which he lives.