The phase in which the moon is not visible from earth is called the "new" moon. It happens when the moon is aligned between the sun and the earth (every 28 days), which causes the side of the moon that we usually see to be in shadow.
In the new Moon phase.
New moon
the new moon
Full Moon
The new Moon "phase" is when the Moon is (more or less) in front of the Sun. We cannot normally see the Moon in this phase. If the Moon is exactly in front of the Sun, the Moon covers the Sun and we see a solar eclipse.
We see the full moon {the phase}.
In the new Moon phase.
After a week from new moon, you'll see a half moon. This is more correctly called the First Quarter phase of the Moon.
New moon
the new moon
Two weeks after the waning gibbous phase of the moon you will see a new moon.
new moon
Full Moon
Full Moon
Full Moon
full moon
The phase of the moon you see depends on how much of the sunlit side of the moon faces earth.