'I'm a black ocean, leaping and wide, / Welling and swelling I bear in the tide. / Leaving behind nights of terror and fear / I rise / Into a daybreak that's wondrously clear / I rise' - Maya Angelou uses which metaphor in these lines from her poem, 'Still I Rise'?

A metaphor states that one thing is something else. This description, however, is too simple for the way metaphors often work in poetry, literature and speeches. You will often find something being described, or written about, as if it is something else, without the writer ever saying 'x is y' (do you see the mathematical metaphor there?).