A logical data flow diagram is related to the business and its operation. It is unconcerned about how the system will be built. Rather, it describes the business events that occur, as well as the data that is required and produced by each event. The primary distinction between a logical data flow diagram and a physical flow diagram is that a logical data flow diagram focuses on business and related activities. In contrast, a physical data flow diagram focuses on implementing the system. A data flow diagram is a diagram that depicts the flow of data in an information system. There are two different types of data flow diagrams: logical data flow diagrams and physical data flow diagrams.