In Entity Relationship (ER) modeling, one defines entities, attributes and the relationships between entities (Paul et al. Ch11, Chan 2013).
An entity is a thing of significance where information needs to be managed.
As such, what defines "significance"? Is a telephone number an entity or an attribute? Provide examples in business, one supporting the notion.
Please also watch the Data Modeling and the ER Model video at Database Lesson #4 of 8 - Data Modeling and the ER Model(youtube)