: Breaks down the context diagram into major subprocesses, revealing more of the system's internal workings.

: Actions that transform incoming data into outgoing information.

: Repositories where data is held for later use, such as databases or files.

: Decomposes processes further until the logic can be explained simply (e.g., through pseudo-code). File Specifics and Usage How to create a Level-0 Data Flow Diagram (DFD)

To manage complexity, DFDs are organized into levels of increasing detail: