Answer: The cage represents the society and how the restrictions of the society affect the freedom.
Explanation: In this poem we have a comparison between a free bird, that can do anything he wants, with a bird that is inside a cage and sees the other bird. The poem explores the different views of the birds, and the figure of the cage represents how the society may limitate the freedom, wherein the second verse we have the phrase "... his bars of rage.." referring to the bars of the cage, implying the nature of the cage.
