How are departmental stores different from the multiple shops?

This topic is covered in our NCERT solutions. You can refer to the same following the below mentioned link.
https://www.meritnation.com/cbse/class11-commerce/ncert-solutions/business-studies/business-studies/internal-trade/page249-Long-Answers-qno2/1161_5373_34624/discuss-the-features-of-a-departmental-store-how-are-they