Data flow diagrams - Word Drop

A data flow diagram, or DFD, shows how ______ moves through a system. It shows where data comes from, where it is stored, how it is processed and where it goes. Organisations use DFDs to explain how their systems work. They also define the ______ of a system, that is, where it starts and where it ends.

A DFD has four main components. An ______ is a person or thing that interacts with the system. A ______ is something that happens to data and is numbered. A ______ is where data is kept after it has been processed. The letter D means the store is ______, and M means it is manual.

Arrows show the ______ of data, that is, its movement between components. Every arrow must go to or from a process. A process must have at least one input and one ______, otherwise nothing is being transformed. The output cannot contain more data than the input.

To interpret a DFD, follow the arrows to see where data goes between the components. When drawing a DFD, use the correct ______ for each component, and show the correct connections and directions. You must also cover every step of the scenario. An ______ focuses on the information a system uses. A DFD instead focuses on the processes and storage that data passes through.