Data Modeling Concepts

You have just learned about attributes, entities and relationships in an abstract sense. The very important things to take away from this section are the following definitions which are given below:

- An entity describes any person, thing, place, or concept for that data will be collected.
- Attributes are further characteristics or information defined for an entity.
- A relationship is a logical linkage among two entities which describes how the entities are related with each other.

You should now know what each of these terms means in the context of data modeling and so are ready to see how these ideas are used in SQL Server. The subsequent sections introduce more concrete terminology which will rigidly define attributes, entities and relationships in the terms which SQL Server understands.