A physical DFD describes the actual way in which system operates, including personnel, physical locations and media used in transfer of information. A logical DFD attempts to reduce this to the actual data flows and the processes transforming the data without regard to the physical manner by which this is achieved.
DFD kimwili inaeleza njia halisi ambayo mfumo wa kazi, ikiwa ni pamoja wafanyakazi, maeneo ya kimwili na vyombo vya habari kutumika katika uhamisho wa habari. DFD mantiki majaribio ya kupunguza huu kwa mtiririko halisi data na taratibu kubadilisha data bila kujali namna ya kimwili ambayo hii ni mafanikio.