What are data flow diagram (DFD) entities also called due to their role?

In the context of data flow diagrams (DFDs), the term used to describe the entities that interact with the system is "terminators." These terminators represent the external elements that either send information into the system or receive information from the system. Their role is to define the boundaries of the system by showing how it interacts with external sources, such as users, other systems, or organizations.

By identifying terminators, DFDs help in visualizing how data moves into and out of a system, which is crucial for understanding the system's interactions and ensuring all necessary inputs and outputs are documented. This clarity is especially important during the systems analysis phase when the requirements are being gathered.

While "actors" might sometimes be used interchangeably in certain contexts, terminators specifically highlight the role of these entities in relation to data flows rather than their more general behavior within a system. Terms like "connectors" and "interfaces" relate to different aspects of DFDs and system design, but they do not capture the precise role that terminators play in delineating the system's boundaries.