A data flow consists of the sources and destinations that extract and load data,
the transformations that modify and extend data, and the paths that link sources,
transformations, and destinations. The Data Flow task is the executable within the
SSIS package that creates, orders, and runs the data flow. A separate instance of
the data flow engine is opened for each Data Flow task in a package. Data
Sources, Transformations, and Data Destinations are the three important
categories in the Data Flow