I am a Newbie with questions.

I have perceived a question before and this question doesn't go away.
My mobile phone - If it is called, how it can be recognized at the place
where I am and then ring. How my phone can be found at that specific place to be rung? Isn't it amazing? I would like to know the step by step how it is.
Is there any one who knows it would be really appreciated.
It isn't needed to be hurried or rushed. Take time to point out where I should
see to find these greatest curiosity to be filled.

Thanks -

Anyone who has interested please give me help? Thanks -