Just before Old Major dies, he describes a dream he had about a world where animals live free from their masters. After he dies, the rest of the animals on the farm plot revenge against their master mister Jones. Snowball and Napoleon (pigs) are important figures in the new movement. When their master neglects to feed them, the revolution happens and Jones and his men are chased off the farm. The farm is renamed to Animal Farm and Seven Commandments of Animalism were written. Jones eventually came back to recapture the farm, but was defeated. Animal farm expands and life becomes tough for the rest of the animals except for the pigs, who begin to express many qualities of their former master. The Seven Commandments are reduced to only one law which is that all animals are equal but some are more equal than others. In the end the rest of the animals cannot differentiate between human and pig.
It’s a satire about the Communist takeover of Russia. The pigs represent the Communist leadership and the rest of the animals represent different parts of Russian society and how the takeover affects them.