Final answer:
A Data Store is used in a DFD to represent data that the system stores because one or more processes need to use the data at a later time.
Step-by-step explanation:
For example, let's consider a system for an online shopping website. The customer's order details, such as the items purchased, their quantities, and the shipping address, may be stored in a Data Store. This data can then be used by other processes, such as the process to generate an invoice or update the inventory.
Data Stores are an important component in DFDs as they help in visualizing the flow of data and identifying the dependencies between processes.