What is the deference between "gamble" and "bet"

Question

PrATT’s risk-Averse insurAnCe PreMiuM:

John Pratt’s closely related definition of risk-aversion approaches the problem as one of insurance. Let us define gamble z as a fair bet. It yields +z with probability ½, and the opposite outcome −z with equal probability ½. The question now is that of the insurance premium π that a risk-averse agent would pay to avoid z , despite the zero expected value of that bet. 

Answer 1

gamble = قمار

bet = شرط بندی