ER Model Google Professional Data Engineer GCP

ER Model is based on – Entities, their attributes and relationships among entities.
An entity represents real-world entity with properties called attributes like chair with size.
Entity is represented as tables also called relations
Columns in table represent attributes or properties
Relations are normalized to store atomic values.
Every row is unique and is a collection of all attributes for a entity’s instance
Relationship refers to logical association among entities, mapping entities to each other.
Cardinality is number of association between two entities similar to parent-child and is – one to one, one to many, many to one or many to many.