Explanation:

Retailer is the one who sells goods/services directly to consumers for their personal or non-business use. Retailers are business entities which act as an intermediary between producer & consumer of goods. Retailer purchase goods/services from wholesaler or distributor and sells to end customers at marked-up prices. They are intermediaries between consumer and wholesalers (or manufacturers).
Retailers play an indispensable role in creating a market for a product or promoting a product because they are the one who can influence consumer purchasing behavior. They purchase products from manufacturers or from wholesalers, who keep the products in warehouses as storage.

They have huge shops, supermarkets etc. where they organize all the different type of products which are available for customers to buy. End consumers can directly come to such retail outlets and purchase these goods.