In a DFD, external entities are represented by a

Explanation

Concepts: There are four symbols in the DFD language, that is, processes, data flows, data stores, and external entities, each of which is represented by a different graphic symbol. An external entity is a person, organization, organization unit, or system that is external to the system, but interacts with it (e.g., customer, clearinghouse, government organization, accounting system) An external entity sends or receives data from the system. It is represented by a rectangle. Important Points: A process is an activity or a function, that is, performed for some specific business reason A data flow is a single piece of data (data element), or a logical collection of several pieces of information (e.g., new chemical request) A datastore is a collection of data that is stored in some way (which is determined later when creating the physical model)