N 씨, N 님

1. It is an expression to use as a person's title, and to express the person who is polite.
   시진 씨 (Mr. Shi Jin)
   지영 씨 (Ms. Ji Young)
   명주 씨 (Ms. Myung Joo)
   리차드 씨 ( Mr. Richard)

2. 'N 님' is a polite expression than 'N 씨'.
   시진 님 (Mr. Shi Jin)
   지영 님 (Ms. Ji Young)
   명주 님 (Ms. Myung Joo)
   리차드 님 ( Mr. Richard)