This Bank Management System ER Diagram is used in database management systems to get a rough idea of the relationships between the entities in a database system. In general, an entity is any real-life object with attributes that may or may not exist physically in the real world. A person, a student, and so on are physical entities, whereas bank accounts exist only logically. Attributes are general properties of an entity that allow us to distinguish it from other entities. Multiple entities may share one attribute. A student entity, for example, has attributes similar to a school name, and a teacher entity has the same attribute as a school name.