SSIS is short for SQL Server Integration Services which is part of Microsoft and it is an enterprise data integration, data transformation and data migration tool which is built into Microsoft's SQL Server database. SSIS can be used for a variety of integration-related tasks, such as analyzing and cleansing data and running extract, transform and load processes to update data warehouses. SSIS is a tool which is used for perform ETL operations likes extract, transform and load data and ETL processing is common in data warehousing applications. At a high level SSIS provides the ability to retrieve data from just about any source perform various transformations on the data likes convert from one type to another and convert to uppercase or lowercase, perform calculations. A package is an organized collection of connections, control flow elements, data flow elements, event handlers, variables, parameters, and configurations, that you assemble using either the graphical design tools that SQL Server Integration Services provides, or build programmatically.