A big-box store, a hyperstore, a supercenter, a superstore, or a megastore is a physically large retail establishment, usually part of a chain of stores. The term sometimes also refers, by extension, to the company that operates the store. The term "big-box" references the typical appearance of buildings occupied by such stores.
Commercially, big-box stores can be broken down into two categories: general merchandise (examples include Walmart and Target) and specialty stores (such as Home Depot, Barnes & Noble, IKEA or Best Buy), which specialize in goods within a specific range, such as hardware, books, furniture or consumer electronics, respectively. In the late 20th and early 21st centuries, many traditional retailers and supermarket chains that typically operate in smaller buildings, such as Tesco and Praktiker (the latter which is defunct since 2014), opened stores in the big-box-store format in an effort to compete with big-box chains, which are expanding internationally as their home markets reach maturity.