Explain the categories of Data Models
Answer:-
1. High-Level (Conceptual) Data Models
- These models use concepts that are close to how users naturally think about data.
- They describe data using entities, attributes, and relationships.
- Entity: A real-world object or concept, like an employee or project, represented in the database.
- Attribute: A property or detail of an entity, such as an employee’s name or salary.
- Relationship: A connection between two or more entities, for example, an employee works on a project.
2. Low-Level (Physical) Data Models
- Describe how data is stored physically on storage devices like magnetic disks.
- Focus on storage details such as file formats, indexing, and data structures.
- These models are mainly used by database and system specialists, not by regular users.
3. Representational (Implementation) Data Models
- Provide a way to represent data that is easy to understand for users, yet still close to how data is actually stored.
- Act as a bridge between high-level and low-level models.
- They hide complex storage details but can be directly implemented on a computer system.
- Example: Relational model, which uses tables to represent data.