Answer and Explanation:
These terms are defined as:
1. Entity:
An entity can be defined as any object that exist physically. it can be referred to any object that is distinguishable, singular and can be recognized like a firm, a person, etc.
2. Attribute:
An attribute can be defined as the specification of any entity.
For instance, if a bike is an entity then wheels, etc are its attributes.
3. Relationship:
It can be defined as any link or connection that exist between 2 entities.