What diagram notation is best for showing data stores and data flow between processes?

• A. Context Diagram
• B. Data Flow Diagram
• C. E-R Diagram
• D. UML

Answer: (B)

Data flows and data stores are best represented by a diagram that models how data moves through processes, where it is stored, and how it is transformed. A Data Flow Diagram provides that focus by showing processes, data flows between them, external entities, and the data stores where information rests between steps. The arrows depict how data moves, while the data stores indicate where information is kept, making it easy to trace data paths and storage across the system.

Context diagrams show system boundaries and external actors but usually omit internal data stores and detailed flows. E-R diagrams model data structures—entities and relationships—rather than movement. UML covers various diagram types, and while some can touch on flow, it’s not specialized for illustrating data movement and storage like a Data Flow Diagram.