Herman, no those aren't multiple grounds. They are connected in a star topology so that they all work to enhance the single ground in the system. Not all grounds are created equal; typically the best (ie, lowest impedance) grounds are from a strategic network of copper rods and additional low-impedance routes to the ground, such as cold water pipes.
And I agree with previous posts in that if you have to ask these questions, you should be consulting with an electrician rather than doing it yourself.
Michael
And I agree with previous posts in that if you have to ask these questions, you should be consulting with an electrician rather than doing it yourself.
Michael