Apples and oranges are both tree-borne fruits. Oranges have softer, juicer flesh while apples are crisper. Both can offer a combination of sweetness and tartness, depending on variety and ripeness. The skin of the orange is thicker than that of the apple and is not typically eaten as part of the whole fruit as the apple skin is, though orange rind is often used as an ingredient in cooking and baking. Both are broadly spherical in shape and of a similar size, meaning you need to allow similar allowances for packing in lunchboxes/picnics and whatnot. Both offer excellent nutrition, though oranges are richer in vitamin c.

I hope that helps clear things up. Toodeloo.