What is a data flow diagram (DFD)?

A data flow diagram (DFD) serves as a graphical representation that illustrates how data moves through a system, showcasing the inputs, outputs, and processes involved. This visual tool is vital for understanding the interactions between different components within a system and aids in identifying data sources, destinations, and storage points. By using standard symbols, such as circles for processes, arrows for data flows, and open rectangles for data stores, DFDs provide a clear and concise view of the data dynamics within a system, which is essential for both analysis and design purposes.

The choice of a graphical representation emphasizes the importance of visualizing data interactions rather than delving into more technical aspects like database structures or outlining user roles. While a detailed representation of database structures may focus on schema and relationships within the data itself, a DFD focuses on how data flows through the processes. Similarly, outlining system functionality is more about documenting specific features and actions rather than the data flow itself.