PPT Slide
Ovals are used to indicate the attributes associated with an entity or relationship (That is, the pieces of information recorded in the database about the entity or relationship) An underlined name indicates that the attribute is a primary key (That is, it can uniquely identify the entity)
Rectangles are used to indicate entities (That is, the representatives or records describing persons, things, or events in the database)
Diamonds are used to indicate relationships between entities. (That is, some association between the data records of different entities)