What is 1984? A brief answer is needed
1984 was written in 1948. Orwell simply switched the last two numbers of the decade to connote the future. The book, really, is not meant to be futuristic: he did not realistically expect the world be this much of a dystopia. Rather, the novel is a satire of two types of government: the extreme liberal (Stalin's Communism) and extreme conservative (Hitler's Nazism). The theme of the work is focused on pain and torture (which Eric Blair "Orwell" saw firsthand): the state's destruction of the individual.
The novel is Juvenalian Satire: it is an attack on these two totalitarian governments. The hero (or antihero) of the satire is Winston Smith, an "Everyman" who is part heroic and part coward, just as his name suggests: "Winston" is after Winston Churchill, the hero for Great Britain during WWII, and "Smith" (is the most common name in the English-speaking world.
The world is divided into three superpowers: Oceania (English-speaking world); Eurasia (non-English whites) and Eastasia (Orient). The novel is set in London, known as Airstrip One.
This is a book written by George Orwell to warn us about a problem that he saw emerging in the years after World War II. This was the problem of governments become more and more (in his mind) totalitarian.
In the book, the government of the country the book is set in (Oceania) controls all aspects of people's lives. It has a surveillance system so that all people (of the middle and upper classes, at least) can be seen and heard by the government spies at all times. The government has gone so far as to change the whole language to limit the ways that people can think.
So the novel is a warning about letting government get to have too much power over the people.