What is Execute SQL Task?

The Execute SQL Task is one of the most widely used tasks in SSIS for interacting with an RDBMS data
Source. 

• The Execute SQL Task can be used for many sorts of things, like
• Truncating staging data table prior to importing,
• Retrieving row counts to determine the next step in a workflow,
• To call stored procedures to perform business logic against sets of staged data.
• The task used to retrieve information from a database repository.

The output from this can be obtained as recordset, multiple variables and other multiple sources.