SSIS DataFlow Task Transformation component, used to split data based on specific conditions. It is similar to a `SELECT CASE`
"The Conditional Split transformation can route data rows to different outputs depending on the content of the data. The implementation of the Conditional Split transformation is similar to a CASE decision structure in a programming language. The transformation evaluates expressions, and based on the results, directs the data row to the specified output. This transformation also provides a default output, so that if a row matches no expression it is directed to the default output." ...more in this MSDN article