Data Driven Framework is a framework which is driven by the different combinations of input and output data.
One way of passing different combinations of data is by Parameterization. In this method, we use different features of QTP. To know more about Parameterization, please visit here.
However in DDF, scripts are written to do parameterization. This kind of framework is useful when the AUT’s functionality must be tested with several inputs and capture the respective outputs. These inputs can be read from an external file such as Database, Excel, Outlook, Text file etc and the respective outputs are written back to the corresponding external source.