Hi...........
BS:
A learning technique involving open group discussion 
intended to expand the range of available ideas
       OR
A meeting to generate creative ideas. At PEPSI Advertising, 
daily, weekly and bi-monthly brainstorming sessions are 
held by various work groups within the firm. Our monthly I-
Power brainstorming meeting is attended by the entire 
agency staff.
      OR
Brainstorming is a highly structured process to help 
generate ideas. It is based on the principle that you 
cannot generate and evaluate ideas at the same time. To use 
brainstorming, you must first gain agreement from the group 
to try brainstorming for a fixed interval (eg six minutes). 

CEG :
A testing technique that aids in selecting, in a systematic 
way, a high-yield set of test cases that logically relates 
causes to effects to produce test cases. It has a 
beneficial side effect in pointing out incompleteness and 
ambiguities in specifications.

Hi sriharsha can u explain me clearly about the CEG
Thanks In Advance