Grounding means earth wire connection. In the event of a short circuit the large short circuit current produced is taken out of the computer cabinet through the psu to the house' earth plate. Without an earth connection your computer will definately go kaput.
thanks for the gyan mate, but I guess we all know that...
But i think there is confusion as to what he meant by this:
Also I saw in one vid that a grounding point is supplied with the cabby and that point has to be tightend with the screws u put on the mobo while attaching it to the cabby ???