1.What is the difference between roles and groups

2. There are two set of user,running on two different set of procedures
How to give a permissions to user on procedures
Ex - Database DB1 having 100 procedures.
user1 uses 50 procedures out of 100 and
user2 uses remaining 50 procedures.

3. Database DB1 having 100 procedures.
Also there are 3 groups Gr1,Gr2 and Gr3
Gr1 have 2 user uses 50 procedures out of 100 and
Gr2 have 5 user uses remaining 50 procedures.

But I want to add Gr1 & Gr2 to Gr3 so Gr3 can have the permission to all 100 Procedures.
How I can add Gr1 & Gr2 to Gr3.

4. How I can setup the dataserver on 4 CPU m/c

Plz give a some idea of all the above questions.