A data flow diagram (DFD) is a graphical representation of the "flow" of data through an information system, modeling its process aspects.
Why DFD technique is so Popular?
Symbols used in DFD
Constructing DFD Models
Developing the DFD model of System
Level O DFD or Context Diagram
Level 1 DFD
Strengths of DFD Model
Weaknesses of DFD Model