How is the "caged bird" described in Angelou's poem, Caged Bird?

The caged bird is presented in stark contrast to the free bird. The caged bird is one who "stalks / down his narrow cage" (8-9) while in captivity. He finds no joy in his surroundings like the free bird does; instead, he is hindered by the bars of the cage and is unable to imagine a world outside his immediate circumstances. His song, the poem suggests, is one that derives from the pain and loneliness of being caged. The subject matter of the song is freedom, or the ability to travel through the world without being held back.