What do each of the four symbols in a DFD represent? Explain the ...

[sjones]

What do each of the four symbols in a DFD represent? Explain the terms used in describing the processes in the DFD.
 
  What will be an ideal response?

Question 2

The most common format used for data modeling is ________ diagramming.
 
  A) Entity-class
  B) Entity-object
  C) Entity-subject
  D) Entity-relationship

[tsternbergh47]

Answer to Question 1

DFD symbols consist of four symbols that represent the same things: data flows, data stores, processes, and sources/sinks (or external entities). A data flow can be best understood as data in motion, moving from one place in a system to another. A data flow is data that move together, so it can be composed of many individual pieces of data that are generated at the same time and that flow together to common destinations. A data store is data at rest. A process is the work or actions performed on data so that they are transformed, stored, or distributed. When modeling the data processing of a system, it does not matter whether a process is performed manually or by a computer. Finally, a source/sink is the origin and/or destination of the data.

Answer to Question 2

D