DBMS (or database management systems) are software which are used to maintain and assess all of the data present in a database.
Supermarkets have large databases of data. The data stored on these databases contain important information such as the expiration dates of food, new shipments of items being logged, which items need to be restocked if they have run low etc
Business use of DBMS in supermarkets
Supermarkets don't just use DBMS for grocery and stock purposes.
The scanners you see present on a stores checkout take every item that is scanned and add it to their DBMS. The information gathered is used by departments such as marketing and buying to make important sales decisions.
With this information, supermarkets are able to assess which items/brands are popular, which lines they should discontinue and they use this information to predict future buying trends so they can try and gain a bigger share of the market over their competitors.
Consumer use of DBMS in a supermarket
The DBMS used by a supermarket are used by you, the consumer, particularly when you are ordering your groceries online.
The DBMS stores data from your previous orders, making it easier for you to find what you always buy and add it to your order. It also stores your address and payment details making the delivery and overall buying process shorter and more convenient.