Transporting data from a source to its destination.

The primary purpose of the data flow task is to move data from a source to a destination.
Also, in the data flow is where transformations are performed.
Moving data and transforming it constitutes the bulk of ETL (Extract-Transform-Load) work done in a BI solution.

A package’s data flow(s) contain the following:

• Data Flow Pipeline: This is where data flows through from sources, into transformation and destination.
• Data Flow Sources: The beginning of data into the pipeline.
  This component provides the ‘E’ in the ETL.
  Examples: DataReader, Excel, Flat file, OLE DB, XML.
• Data Flow Destination: The target of the data.
  This component provides the ‘L’ in the ETL.
  Examples: DataReader, Excel, Flat file, Recordset, SQL Server, OLE DB, XML.
• Data Flow Transformations: Changes data coming from the source according to business rules.
  This component provides the ‘T’ in the ETL.
  Examples: Row or Rowset, Split and Join, BI.
• Connection Managers: Wire-together data data sources and destinations.
  Data Viewers: Provides a preview of data flowing through the pipeline.
  Viewer types: Grid, Histogram, Scatter Plot, Column chart.