What are the strategic benefits to compensate for the fact that White's giving up the bishop voluntarily and so early in the game in the below variation? What does White hope to get back out of the opening?

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1. e4 e5 2. f4 exf4 3. Nf3 d5 4. exd5 Nf6 5. Bc4 Nxd5 6. Bxd5