Perquisite is a payment or profit received in addition to a regular wage or salary; especially, a benefit expected as one’s due; a perk: “The payment of bonus on festival of Diwali is a tempting perquisite for the employees to stick to the company.”
Prerequisite means required or necessary as a prior condition: “Scoring more than 60% in the entrance test is a prerequisite to get admission to the PhD course in the University.”
Requisite means required; essential or something that is indispensable: “To be PhD is a requisite to apply for a post of college principal.”
