Description Data Examples A column (or group of columns) that exists to create relationships between two tables, linking to the primary key in another table. Diagrams that communicate which tables are in the database, which fields are in each table, and how each table is related through primary key/foreign key placement. A column in a relational table/database that serves as a unique identifier. Structured set of data generally held in a computer allowing access by many potential users. Graphical representation of an information system, illustrating relationships among people, objects, places, and events within that system. Database ER (entity-relationship) diagrams Foreign key Primary key Relational database diagrams