Here's the breakdown of the Moon's position during a full moon:

* Sun, Earth, Moon alignment: The Sun, Earth, and Moon are aligned in a straight line, with the Earth in the middle.

* Moon's position: The Moon is on the opposite side of the Earth from the Sun.

* Why we see the full moon: The entire sunlit face of the Moon is visible from Earth.

Think of it like this: the Sun is shining on the Moon, and the Earth is in the middle, blocking the Sun's light from reaching the Moon's far side. That's why we see the whole Moon illuminated.