In data modeling, what do we call something in the user's environment that can be identified and that users want to track?

Introduction / Context:
Before designing tables, we must decide what to model. ER modeling begins by identifying the key things—people, places, events, or concepts—that the business cares about and wants to store data for.

Given Data / Assumptions:

• The focus is on a real-world thing of interest to users.
• It must be identifiable (instances distinguishable from each other).
• We need the correct modeling term for such a thing.

Concept / Approach:
An entity represents a class of things of interest. Each occurrence is an entity instance (tuple/row in the relational mapping). Entities have attributes (columns) and relationships to other entities. Defining entities correctly provides the foundation for a maintainable schema.

Step-by-Step Solution:

Verification / Alternative check:
Any ER methodology starts by listing candidate entities from requirements, use cases, or user interviews.

Why Other Options Are Wrong:
Attribute: A property of an entity, not the thing itself.
Identifier: A key for entities, not the entity.
Relationship: Connects entities, not a thing in the domain.
Domain: A set of allowable values for an attribute.

Common Pitfalls:
Over-specifying attributes before the entity set is clear; start with entities and relationships first.

Final Answer:
Entity