1.1. Data Model
Entities In data modelling (a first step in the creation of a database), an entity is some unit of data that can be classified and have stated relationships to other entities.
Attributes In computing, an attribute is a specification that defines a property of an object, element, or file. It may also refer to or set the specific value for a given instance of such.
Entity Relationship Diagram An entity relationship diagram (ERD) shows the relationships of entity sets stored in a database. An entity in this context is an object, a component of data.