Fano plane

In finite geometry, the Fano plane (after Gino Fano) is the finite projective plane of order 2, having the smallest possible number of points and lines, 7 each, with 3 points on every line and 3 lines through every point. The standard notation for this plane, as a member of a family of projective spaces, is PG(2,2) where PG stands for "Projective Geometry", the first parameter is the geometric dimension and the second parameter is the order.