ssas Aggregation design wizard

Hi everyone

What is aggregation design wizard, does it help with precomputing the aggregations. If it does, how? and what options I need to select to precompute ALL aggregations when the cube is processed.

I need help in understanding how it works and when its done, where does its code reside as to "Design aggregations untill " options are concerend.

Thanks much for your help on this

-Sarah