Όμορφος is "that pleases with its appearance", with one word: beautiful. Ωραίος is "who has desirable characteristics, provokes a pleasing felling", with one word: nice. If someone is ωραίος/ωραία in appearance, he/she is όμορφος/όμορφη. But someone can be ωραίος τύπος=nice guy, which is different from όμορφος τύπος=beautiful guy. Sometimes they can be used interchangeably. P.e. είναι ωραίος can mean "he is handsome, he is nice, etc". Έχει όμορφη ψυχή=(Metophor.) She has a beautiful soul.