Entity–Relationship Modeling — Definition of Entity Type In database design, which option best defines an entity type as used in the ER (Entity–Relationship) model?

Introduction:
The ER model is foundational for database analysis and design. This question verifies that you understand what an entity type represents within that model and how it differs from departments, processes, or attributes.

Given Data / Assumptions:

• The focus is on definitions from the ER methodology.
• An entity type groups instances sharing common properties.
• Only one option matches the textbook definition.

Concept / Approach:
An entity type is a named collection of similar things of interest to the organization, such as Customer, Order, Product, or Supplier. It is not a single attribute, nor is it a department or process. Attributes describe entities; processes transform data; departments are organizational units, not data categories per se.

Step-by-Step Solution:
1) Recall the ER building blocks: entities, attributes, and relationships.2) Match the definition that describes a broad category of data (e.g., Customer) rather than a single value or organizational structure.3) Select the option that states “a major category of data about people, places, or things.”

Verification / Alternative check:
ER textbooks consistently define an entity type as a set of objects (entity instances) sharing attributes and identity, distinct from processes or departments.

Why Other Options Are Wrong:

• Departments: Organizational units, not data categories.
• Application software: Tools used by the business, not data of interest.
• Business processes: Activities/tasks, not entity sets.
• Attribute value: A property of an entity, not the entity type itself.

Common Pitfalls:
Confusing entities with attributes (for example, treating “Email Address” as an entity rather than an attribute of “Customer”).

Final Answer:
A major category of data about people, places, or things