characteristics relationships

Hi Experts,

Can some one explain the use of characteristics relationships with an example.

As far i understand, Characteristics relation ship is created for the characteristics of the real time infocube. On selecting the Activity as type, list of available characteristics in the real time info cube arrives.

On selecting one of the characteristics, source attribute and target attribute arrives.

Please clarify what does the mapping of source attribute with target attribute performs.

Regards

Suresh Kumar