This information can be understood and managed by the software. These data objects can be printer, user, sensor which are external entities. Things in the form of reports, visualizations, etc. Events such as interruptions, alarms. Specific role in the company as manager, engineer, salesman. Business units, for example division, team. places, for example, production workshops. Structures e.g., employee records, student records, accounts, files. Let's take an example of Vehicle data object which has the following attributes Make, Model, Color, Owner and Price. Each data object instance can be identified by a unique identifier as in a university student is recognized by his roll number. Attributes: Properties of data objects are defined by attributes. These can be of three types Naming Attributes, Descriptive Attributes and Referential Attributes.1. Naming attributes: These attributes are used to name a data object instance. For example, in a vehicle data object, the make and model are naming attributes.2. Descriptive attributes: These attributes are used to describe the characteristics of a data object. For example, in a vehicle data object, color is a descriptive attribute.3. Referential Attributes: These attributes are used to create reference to another object in a table. For example, in a vehicle data object Owner is the referential attribute. Relationships: Represents the connection between data objects. For example the relationship between shopkeeper and others