Explanation:

A departmental store is a large-scale retail organisation having a number of departments under one roof. Each department specialises in one particular kind of trade. All these departments are centrally organised and are under one united management and control.
According to Converse, “A departmental store is a retail shop handling several classes of goods including women’s wear or dry goods, each class being separated from others in management, accounting and location.”

Clark defines it as “that type of retail institution which handles a wide variety of merchandise under one roof with the merchandise grouped into well-defined departments which is centrally controlled.” Thus, a departmental store is an organisation of several retail stores carried on in one building and under united controlled management.