The bottom one has rise, meaning vertical orientation of the handgrips to the stem clamp, and more sweep, meaning the handgrips reach back a little more. The rotation of bars like this should be that when you look at the bike head-on at handlebar level, the handlebar should smile back at you. Naturally, you can roll it back and make it frown, but then your wrists get uncomfortably cocked and the grips ten to slide off if they're not screwed on. Or you can roll it forward and turn the sweep into an even bigger grin. Somewhere in the middle is preferable.