Actors:
Actors are objects represented in the functional model that produce or consume data. An actor may store some data for further processing steps.
Data Stores:
Data stores are store house of data represented in the functional model. A data store could only store or consume data, but could not produce data.
Below is an example detailing DFD for computing volume and surface area of a cylinder - Enjoy!!
Object identified - Cylinder
Processes identified - Compute volume, compute surface area
Data flows identified -
Input : radius, height
Output: volume, surface area
The DFD is as shown below -

Actors are objects represented in the functional model that produce or consume data. An actor may store some data for further processing steps.
Data Stores:
Data stores are store house of data represented in the functional model. A data store could only store or consume data, but could not produce data.
Below is an example detailing DFD for computing volume and surface area of a cylinder - Enjoy!!
Object identified - Cylinder
Processes identified - Compute volume, compute surface area
Data flows identified -
Input : radius, height
Output: volume, surface area
The DFD is as shown below -