Animal farm is undoubtedly a "fairy story" (its sub title) or fable as it relates the story of farm animals trying to survive. The animals possess human qualities and adopt human characteristics in the fight for what is rightfully theirs. A fable is an
imaginative narrative, usually with animal characters, that illustrates a moral
and is a technique used because it is straightforward and easy to follow, the language usually being uncomplicated. The allegorical nature allows anyone to read the novel without the need to understand the historical significance although it
makes the characters easily identifiable for those who know the historic parallels.
An allegory is a form of extended metaphor as the comparison is sustained throughout. Orwell despised all forms of oppressive governance and was himself disillusioned by the abuse of power he had seen. In his allegorical fable then he uses satire to show his disapproval of the "system." Satire makes light of a very serious issue by making it almost ridiculous and is a literary technique widely used.
The very fact that he uses animals with pigs as the leaders shows his lack of respect for Russia's leaders during the Revolution. He satirizes the way the communists (the pigs ) under Stalin (Napoleon), exploited the Russian people (the other animals) just as the Tsar (Mr Jones) had previously.
Irony features throughout in all its forms. It is ironic that replacing one leadership type with another does not help the animals.
in those days they had been slaves and now they were free (Ch 9)
Ironically,it made no difference. Irony is obvious in the mantra" Some animals are more equal than others" and ultimately, it is ironic at the end when the pigs are indistinguishable from the humans and they toast not, Animal farm but to “The Manor Farm” .