What is the difference between these two prescriptioins? Which one is stronger?

Well the first one listed is the stronger correction, having a half diopter more correction in the astigmatism. The other difference is the base curve, with the second lens having a slightly higher curvature. When you are fitted for your lenses, often the doctor will try different sizes because over time, the lens fit in relation to the cornea can change, so this, or the power increase may be why the doctor chose to change the curve or brand, in order to get the best fit for your eye.