what is erd

An Entity-Relationship Diagram (ERD) is a type of flowchart that illustrates how entities, such as people, objects, or concepts, relate to each other within a system. ERDs are most often used to design or debug relational databases in the fields of software engineering, business information systems, education, and research. ERDs are composed of entity types, which classify the things of interest, and specify relationships that can exist between entities. ERDs are usually drawn in a graphical form as boxes (entities) that are connected by lines (relationships) which express the associations and dependencies between entities. ERDs are related to data structure diagrams (DSDs), which focus on the relationships of elements within entities instead of relationships between entities themselves. ERDs are also often used in conjunction with data flow diagrams (DFDs), which map out the flow of information for processes or systems. ERDs can help businesses document existing databases and troubleshoot logic or deployment problems, spot inefficiencies, and improve processes when undertaking business process re-engineering. ERDs can also be used to design and model new databases and identify any logic or design flaws before theyre implemented in production.