DTP in BI7.0

What is the difference between the infopackage in transformation and the infopackage in the DTP?

My understanding is that we only need to load to PSA using the transformation and then using DTP we need to load into the datatarget, but in the infopackage in the transformation we have the option to select the infocube as the datatarget also. What would happen if load into the infocube directly using the transformation.

Please clear my confusion.

Thanks

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