Perfect competition is THE example for pricer taker because it contains a relatively large number of participants that trade an identical product. Participants are free to enter and exit the market and everyone has complete knowledge of all prices.

Each buyer competes against thousands, hundreds of thousands, or even millions of other buyers when they seek to purchase a good. Each seller competes against thousands, hundreds of thousands, or even millions of other sellers when they seek to sell a good.

Sellers do not sell to a buyer trying to pay less than going market price, because thousands, or even millions of other buyers are willing and able to pay the going price. Buyers do not buy from a seller trying to charge more than going market price, because thousands, or even millions of other sellers are willing and able to charge the going price.

Each participant is an insignificant part of the overall market. Should a given buyer decide to buy more or less or nothing at all, the market is unaffected. Should a given seller decide to sell more or less or nothing at all, the market is unaffected.

Price-taking buyers and sellers face perfectly elastic demand and supply curves. For example, a perfectly competitive seller faces a perfectly elastic demand curve, one that is horizontal at the market price. It can sell any quantity that it wants at the going market price. A perfectly competitive buyer faces a perfectly elastic supply curve, one that is horizontal at the market price. It can buy any quantity that it wants at the going market price.