Viajero is correct as usual.
The first shows how many miles you were earn based upon miles actually miles flown and the second the points you will earn. For fare classes:
A,F, and P, you will earn 150% of the miles flown and 1.5 points per mile flown, a 1000 mile flight will earn 1500 miles and 1500 points;
C, D, I, J will earn 125% and 1.5 points per mile flown, a 1000 mile flight will earn 1250 miles and 1500 points;
B, Y will earn 100% of miles flown and 1.5 points per mile flown, a 1000 mile flight will earn 1000 miles and 1500 points;
H, K, W will earn 100% of miles flown and 1 point per mile flown, a 1000 mile flight will earn 1000 miles and 1000 points;
M, V, L, R will earn 50% of miles flown and 1 point per mile flown, a 1000 mile flight will earn 500 miles and 1000 points;
G, O, S will earn 50% of miles flown and .5 points per mile flown, a 1000 mile flight will earn 500 miles and 500 points.