Understanding Data Flow Diagrams (DFDs)

What does DFD stand for?

• Data Function Diagram

• Data Flow Diagram

• Data Format Diagram

• Diagram Flow Data

What is the primary purpose of a DFD?

• To document the user interface of systems

• To list all the components of a system

• To illustrate the programming logic behind systems

• To show how data moves around a system

What does a rectangle symbolize in a DFD?

• An external entity

• A process

• A data store

• A data flow

In a DFD, what does an external entity represent?

• A database or file where data is stored

• The movement of data between components

• A process that transforms data

• An object, often a human, that interacts with the system

How should a data store be visually represented in a DFD?

• As an arrow

• As a triangle

• As a circle

• As a rectangle with a missing edge

What is a Level Zero DFD?

• A detailed breakdown of all system processes

• A high-level overview of the system

• A DFD that includes external entities only

• A DFD that focuses on data storage

In the backup system example, who initiates the backup process?

• The file manager

• The database

• An IT technician

• The storage device

What role does an IT technician play in the backup system example of a Level Zero DFD?

• Initiates the backup request

• Processes the data

• Receives the final data

• Stores the data

What distinguishes a Level One DFD from a Level Zero DFD?

• It provides a more detailed breakdown

• It only includes external entities

• It focuses solely on data storage

• It is a simpler overview

In a Level One DFD, how should data flow be represented?

• In multiple directions between processes

• Directly between external entities without processes

• In one direction to avoid confusion

• Without labels for simplicity