Data Flow Diagrams and Flowcharting Concepts (Lecture Notes)

Vocabulary flashcards covering DFD concepts, flowcharting symbols, and related terms from the lecture notes.

Data Flow Diagram (DFD)

A graphical representation of how data moves through a system, showing data flows, transformation processes, data stores, and data sources.

Data flow

A data item that travels between elements of a DFD.

Transformation process

A function or operation in a DFD that converts input data into output data.

Data source

An external entity that provides data to the system modeled by a DFD.

Data storage

A place where data is kept for later use, such as databases or files; represented as a data store in a DFD.

Merchandise

Goods for sale; in the narrative, a data element representing items being purchased.

Cash

Money received in a transaction; in the narrative, data representing payment.

Payment

The act or data indicating payment for goods; included as a data flow in the scenario.

Register tape

The printed record produced by a cash register; used as a data store/flow in the narrative.

Customer

The external party who purchases goods; acts as a data source in the DFD example.

Data flow element

A component in a DFD representing the movement of data between processes, stores, and sources.

Data storage element

A component in a DFD representing where data is stored (data store, database, file).

Flowchart

A diagram that uses standardized symbols to depict the steps, decisions, inputs/outputs, and flow of control in a process.

Data flows symbol

The symbol or line that represents movement of data between elements in a flowchart or DFD.

Document symbol

Flowchart symbol representing an input or output document.

Display symbol

Flowchart symbol representing a display device or monitor.

Processing symbol

Flowchart symbol representing a process or operation.

Database symbol

Flowchart symbol representing a database or data storage.

Magnetic tape symbol

Flowchart symbol representing data stored on magnetic tape.

Communication link

A connection (often telephone) that links a local system to a remote database or service.

Terminal

A device used to input data or view information in a system.

Master file

The primary dataset that is updated by transactions in a database or file system.

Magnetic tape

A sequential storage medium used to store and retrieve data.

Querying a database

The process of retrieving data from a database by performing a query.

Printing the query result

Outputting the results of a database query to a report or printout.