Entities in the entity-relational consist of stored data points on people, places, and things, each having certain attributes that constitute their domain. The cardinality, or the relationships between entities, is also mapped. The entity relationship model is based on the notion of real-world entities and their relationships. An entity set is created while formulating the real-world scenario into the database model that is dependent on two vital features, as follows:

• Entities and their attributes: For example, a student entity may have a name, class, and age as attributes.
• Relationships among entities: For example, an employee works at a department, and a student enrolls in a course. Here, Works_at and Enrolls are called relationships: