Helps the ski "float" and turn easily without catching an edge. Camber underfoot: Provides grip and stability on firm snow.
A narrower "waist" (the middle of the ski) allows for quicker transitions from edge to edge on groomed runs (piste), which is where most beginners spend their time. Profile (Rocker/Camber): how to buy skis for beginners
Look for "soft flex" skis. They require less power to bend, making it easier to initiate turns and more forgiving if your technique isn't perfect yet. Helps the ski "float" and turn easily without