수상자 is award receiver; winner is more like 우승자/승자
You also win a prize. For example, the Nobel Prize winner is translated to 노벨상 수상자.
but you would not limit the meaning like that... award receiver must also be accepted
award/prize receiver, award/prize recipient, and awardee are accepted. I am not limiting the meaning, but I am saying you can't say 수상자 or a winner is more like one over the other.
受賞者는 médaille을 땄습니다. (採りました、授かりました, collected, picked up, accepted, was awarded)