It maps the processes involved in transferring data from the input to the file storage and reports generation.

Data flow diagrams use symbols (e.g., rectangles, circles, and arrows) and text labels to display inputs, outputs, storage points, and the routes between elements. 

Data flow diagrams typically are divided into logical and physical

• The logical data flow diagram represents the flow of data through a system to perform certain business functions. 

• The physical data flow diagram represents the implementation of the logical data flow.

The history of data flow diagrams

The beginning of data flow diagrams popularity dates back to the end of the 70s, arising from the book written by computing pioneers Ed Yourdon and Larry Constantine. Since then, they are widely used in computer science.