What does a data flow diagram represent?

A data flow diagram (DFD) is a crucial tool in system analysis and design that visually represents the flow of data within a system. It illustrates how data is input, processed, stored, and output, highlighting the relationships between different processes and data sources. This enables analysts to understand how data moves through a system, which is essential for identifying requirements and documenting the system's functions.

By mapping out processes and data stores, a DFD helps to clarify how information is transformed and utilized, making it easier for stakeholders to communicate and collaborate on system development. The use of various symbols in a DFD, such as circles for processes, arrows for data flow, and open-ended rectangles for data stores, further enhances its effectiveness in conveying complex information in an easily digestible format.

This focus on data movement and processing is what distinguishes DFDs from other project management tools that deal with financial aspects, tasks, or team roles, which are not the primary concern of a DFD. Therefore, the representation of data flow, processing, and storage is central to a data flow diagram's purpose and effectiveness.