What is infix, prefix and postfixexpressions in data structures?

Infix notation: A+B

Operators are written in-between their operands. Expression X * (Y + Z) / P is means: "First add Y and Z together, then multiply the result by X, then divide by P to give the final answer."

Postfix notation : A B +

Operands are written before their operators. Expression given above is equivalent to X Y Z + * P /

Operators evaluation is always left-to-right, we will not consider brackets for the order.

Prefix notation : + A B

Operands are written after their operators. Expression given above is equivalent to / * X + Y Z P

Operators evaluation is always right-to-left, we will not consider brackets for the order.