Which diagram shows entities and their attributes?

• A. UML diagram
• B. E-R diagram
• C. Flowchart
• D. Data Flow Diagram

Answer: (B)

Entities and their attributes are modeled most directly by an entity-relationship diagram. This type of diagram is built to represent real-world objects (entities) such as Customer, Product, or Order, and to list the properties of those objects (attributes) like Customer name, address, or Order date. It also shows how different entities relate to one another through relationships, which is essential for understanding how data items connect in a database design. Typically you’ll see rectangles for entities with their attributes shown alongside or connected as ovals, and diamonds or lines indicating the relationships between them.

This focus on what data exists (entities) and what properties describe them (attributes) is distinct from other diagrams. Flowcharts map the sequence of steps in a process; data flow diagrams depict how data moves between processes and stores; UML diagrams can model classes and broader software structures, including methods, but the ER diagram is specifically the standard choice for representing entities and their attributes in data modeling. For a simple illustration, a library system might have an entity like Book with attributes such as ISBN, title, and author; a Member entity with member_id and name; and a Loan relationship linking Members and Books.