SAP Data Provider 
The SAP Data Provider (called Data Provider for short in this documentation) is a standard interface for retrieving data used by controls in SAP GUI.
Data Provider
Manages the data
Maps the data in standard Windows data types and data objects
Controls the data conversion
The Data Provider consists of the following components:
ABAP function modules
ABAP function modules represent the interface of the DataProvider to the application programmer or wrapper programmer. They work with data types that are common in ABAP, for example, internal tables.
Function Calls in SAP GUI
Two function calls exist in SAP GUI which can be reached using RFC. One function sends a table to SAP GUI, the other retrives a table from SAP GUI. The table transferred with this call is a data object.
LocalTables object
The LocalTables object manages all tables in a data pool that is global within a process space.
DataProvider object
The DataProvider object makes it possible to access data objects in the LocalTables object. You can request references to data in the LocalTables object or store it there.
Since the DataProvider object works with data types and data objects that are valid as Windows standards, the user does not need any knowledge of internal tables or ABAP data types.
In addition, the DataProvider object offers access to ftp: and http: servers, as well as files saved locally or on file servers.

The Data Provider is used in most ActiveX controls that are provided by SAP. Examples for such controls are the Text Edit Control, HTML Control, Tree Control, and Desktop OfficeIntegration.
They need the Data Provider for the following reasons:
With the standard mechanism of the Automation Queue, it is not possible to transfer volumes of data over 256 bytes in a method call, or BLOB data (binary large object) such as Office documents, photos, or editor contents.
External data sources (that is, sources outside of the SAP system or the current ABAP program) must first be made accessible. Examples for such external sources are the Info Repository and local files.
The SAP Data Provider is only available for Windows platforms (Windows95 or Windows NT as of 4.0).