concentration and meditation

My idea of meditation is not any concentration or focusing attention on any particular deity or god. Focusing and concentration are when you chant a ‘mantra’ or when you seek a favour from your deity. Even then what is concentration? On what do you concentrate? Is it on the form of the god, the humanized concept of the form or ‘linga’? When I tried it in my student days as a boy, I was confused as to where to end the periphery of the form. Should I concentrate on the face or the eyes? Or the conceptualized and elaborately described form of the goddess or god, or on the detailed image represented by the stone sculpture? The focusing can be on the whole form with the surroundings as well, or merely on the face or the eye. A one-pointed concentration could be on a single eye or even on a point in the centre of the eye when the object of focusing progressively shrinks. The point can further shrink into ‘nothing’ as the point contracts or approaches zero. Only then there will be full focusing.
This ‘nothing’ can then give a feeling of expanse into the whole mental space because the concentration has left the rest of the vast space empty. When the mind expands into the whole infinite space in which everything seems present, but nothing surfaced to attention, one has a feeling that, that inclusion of the whole is real concentration.
I find that as said by J.K., meditation is a state of mind where no thought is present. Some Buddhists call it the ‘the nature of the mind’, or Rigpa. It is said that if you concentrate on the form of the lord you can get visions of the deity. I believe that it is all for getting some boons or acquiring special powers which they think is possible, but not for getting at the Truth.
In the state of mind that is meditation there is a feeling of concentration in an endless expansion of the mind where everything is dynamically dormant.