How to: Characteristics
Let's look at some key characteristics of a federated database:

- **Transparency**: Federated database masks user differences and implementations of underlying data sources. Therefore, the users do not need to be aware of where the data is stored.
- **Heterogeneity**: Data sources can differ in many ways. A federated database system can handle different hardware, network protocols, data models, etc.
- **Extensibility**: New sources may be needed to meet the changing needs of the business. A good federated database system needs to make it easy to add new sources.
- **Autonomy**: A Federated database does not change existing data sources, interfaces should remain the same.
- **Data integration**: A federated database can integrate data from different protocols, database management systems, etc.