What is the Significanc of User Defined Attributes in Siebel Product Administration ?

Hi Experts,

Can some one provided the information about User Defined Attributes in Siebel Product Administration.

1)How these attributes are differrent from the general product Attributes?

2)What is the Importance?

3)How to use this in siebel ?

4)Where this Attributes will be used i.e in Configurator?

5)Provide some good example where i can better use this attributes instead of normal product attributes.

6)is there any document which provides the detailed steps for creation of this User Defined Atributes.

Regards,

Raghavendra Bashetty