Answer:
I have three heads. Cut off one I become stronger. Cut off two I become ten.
you need thousands of me to create a digital image.
I am a protector. I sit on a bridge. One person can see right through me, while others wonder what I hide. What am I?
Without me everyone would lose their head.
I dig out tiny caves and store gold and silver in them. I also build bridges of silver and make crowns of gold. Sooner or later everybody needs my help yet many people are afraid to let me help them.
Give it food and it will live, give it water and it will die.