04-04-2017, 11:30 AM
An Entity Relationship Diagram (ER) is a type of flow diagram that illustrates how entities, such as people, objects, or concepts, relate to each other within a system. ER Diagrams are most commonly used to design or debug relational databases in the fields of software engineering, business information systems, education and research. Also known as ERDs or ER models, they use a defined set of symbols such as rectangles, diamonds, ovals, and connection lines to represent the interconnection of entities, relationships, and their attributes. They reflect grammatical structure, with entities such as nouns and relationships as verbs. An Entity Relationship Diagram (ERD) is a visual representation of different data using conventions that describe how these data are related to each other. For example, the writer, novel and consumer elements can be described using ER diagrams in this way: