Postfix notation, also known as RPN, is very easy to process left-to-right. An operand is pushed onto a stack; an operator pops its operand(s) from the stack and pushes the result. Little or no parsing is necessary.

What is the advantage of postfix expression?

Postfix has a number of advantages over infix for expressing algebraic formulas. First, any formula can be expressed without parenthesis. Second, it is very convenient for evaluating formulas on computers with stacks. Third, infix operators have precedence.

Why do computers use postfix?

The Postfix notation is used to represent algebraic expressions. The expressions written in postfix form are evaluated faster compared to infix notation as parenthesis are not required in postfix.