Atheists, the death penalty and abortion...

[Silver]

Then what is it and at what point does it become one?

Until it leaves its mother's womb, it is a fetus. Before the fetus stage, it is an unrecognizable bundle of cells, which is why abortion is legal. Most rational people consider the infant, out of its mother's womb, a human. I personally believe speech and cognitive processes need to be developed before it can be considered a human.