This data flow diagram is used to graphically represent the flow of data in a business information system. DFD describes the processes that occur in a system to transfer data from the input to file storage and generate reports. Data flow diagrams are classified as logical or physical. The analytical data flow diagram depicts data flow through a system to perform specific business functions. The physical data flow diagram also shows how the logical data flow is implemented. DFD graphically represents the functions or processes that capture, manipulate, store, and distribute data between a system and its environment and between system components.