What is Proposition in Mathematical logic?

A Proposition or Statement is a sentence which has truth value(true/false)
eg: sun rises in the east(T)
      earth is round in shape(F)

Sentence which are not propostion are
eg: what is your name?
      please give me 5 rupees
      shut your mouth
      what a beautiful flower it is!
    
commanding statements, exclamation, questions, request statements are not propostion.