In ER modeling, entities are connected to each other using which construct?

Introduction / Context:
Beyond defining entities and their attributes, a data model must express how entities are associated. This is where relationships enter the picture, defining cardinalities and participation rules.

Given Data / Assumptions:

• We have multiple entities needing meaningful associations.
• We must express business rules like one-to-many or many-to-many.
• We are choosing the correct connector construct.

Concept / Approach:
A relationship captures how instances of one entity are associated with instances of another (or the same) entity. Relationships also carry cardinality and optionality information and may have attributes of their own in certain notations (especially for associative entities).

Step-by-Step Solution:

Verification / Alternative check:
All major ERD notations use relationship symbols (lines, Crow’s Foot, etc.) to connect entities.

Why Other Options Are Wrong:
Entities / Attributes / Identifiers / Domains: These define data elements and types, not the connections between entities.

Common Pitfalls:
For many-to-many relationships, forgetting to implement an associative entity (junction table) leads to poor relational design.

Final Answer:
Relationships