A client dataset uses a provider to supply it with data and apply updates when

• It caches updates from a database server or another dataset.
• It represents the data in an XML document.
• It stores the data in the client portion of a multi-tiered application.

For any client dataset other than TClientDataSet, this provider is internal, and so not directly accessible by the application. With TClientDataSet, the provider is an external component that links the client dataset to an external source of data. 

An external provider component can reside in the same application as the client dataset, or it can be part of a separate application running on another system. For more information about provider components, see Using Provider Components. For more information about applications where the provider is in a separate application on another system, see Creating multi-tiered applications. 

When using an (internal or external) provider, the client dataset always caches any updates. For information on how this works, see Using a client dataset to cache updates. 

The following topics describe additional properties and methods of the client dataset that enable it to work with a provider:

• Specifying a provider
• Requesting data from the source dataset or document.
• Getting Parameters From the Application Server
• Passing parameters to the source dataset
• Handling constraints from the server
• Refreshing records.
• Communicating with providers using custom events
• Overriding the source dataset