Together with 8.a4 and 8.c3, this is one the main lines of this Ruy Lopez system.
1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1b5  3... a7a6  4. b5a4  4... g8f6  5. e1g1  5... f8e7  6. d2d3  6... b7b5  7. a4b3 