The three main components of E-R diagram are Entity, Attribute, and Relationship.
1. Entity:
An entity is a person, place, thing or event for which data is collected and maintained.
2. Attribute:
An attribute is the characteristic property of an existing entity.
3. Relation:
A relation is defined as a set of tuples that have the same attributes. A relation is usually described as a table, which is organized into rows and columns.
