泾渭分明 jīng wèi fēn míng

DEFINITIONS

  1. as rivers Jing and Wei separate clearly (idiom)
  2. to be entirely different

CHARACTERS

泾 jīng name of a river
渭 wèi name of a river in Shanxi
分 fēn divide; small unit of time etc.
明 míng bright, light, brilliant; clear