There are two types of data transforms that may occur in the data transfer process. The first type is explicit from the point view of an SSIS package, the conversion between Unicode characters and non-Unicode characters. This conversion is automatically handled by the tool, which adds an SSIS Data Transform component to the package.
The second type is implicit, the conversion between subtypes of the same data type, such as conversion between DataTime and DataTime2, conversion between REAL and FLOAT. This type of conversion is handled internally by the SQL Server Database engine and there is no need to add a Data Transform component to the package.