A retail store that occupies an enormous amount of physical space and offers a variety of products to its customers. These stores achieve economies of scale by focusing on large sales volumes. Because volume is high, the profit margin for each product can be lowered, which results in very competitively priced goods.

The term "big-box" is derived from the store's physical appearance. Located in large-scale buildings of more than 50,000 square feet, the store is usually plainly designed and often resembles a large box. Wal-mart, Best Buy and Ikea are examples of big-box retailers.