A number of shops under one roof is a

The term that describes a number of shops under one roof is "department store". A department store is a large retail establishment that offers a wide variety of products and services, organized into different departments or sections, such as clothing, cosmetics, electronics, furniture, and so on. Department stores usually have a large floor area and are divided into various sections to offer different products and services to customers. They may also have additional features like restaurants, cafes, or event spaces to provide a more immersive shopping experience. In summary, a department store is a one-stop-shop that offers a diverse range of products and services under a single roof.