What are the main types of objects in the OLE-DB model? Explain.

The functionality of OLE-DB model is divided into two types of objects: consumers and providers.

1 . Consumers are objects (applications or processes) that request and use data. Consumers request data by invoking the methods exposed by the data provider objects (public interface) and passing the required parameters.

2 . Providers are objects that manage the connection with a data source and provide data to the consumers. Providers are divided into two categories: data providers and service providers.
 Data providers provide data to other processes. Database vendors create data provider objects that expose the functionality of the underlying data source (relational, object-oriented, text, and so on).
 Service providers provide additional functionality to consumers. The service provider is located between the data provider and the consumer. The service provider requests data from the data provider, transforms the data, and then provides the transformed data to the data consumer. In other words, the service provider acts like a data consumer of the data provider and as a data provider for the data consumer (end-user application). For example, a service provider could offer cursor management services, transaction management services, query processing services, and indexing services.