>>21394434 (OP)health-wise:
apples have barely any vitamin c
oranges have a lot
the only nutrient that apples have in any meaningful quantity is boron, and since most people are deficient in boron an apple a day is actually a good idea
cooking-wise:
oranges taste better but apples have more versatility, not only can you bake with them but you can pair them with liver and onions for example. desert only vs deserts and savory meals
availability:
apples mog oranges hard here, although it's not really an issue in first world countries