That's true at the moments of First Quarter and Third Quarter phases.
90 degrees (approximately) from the position of the moon, in the direction of the lighted side.
One half of the moon, the side that faces the Sun, is always lighted. But we usually see only part of the lighted side (phases) as the Moon orbits the Earth. When the Moon is directly between the Earth and the Sun (a new moon) none of the lighted side, facing the Sun, is visible from Earth.
The amount of the lighted side of the moon you can see is the same during the first quarter and the last quarter phases. In both phases, half of the moon's illuminated side is visible from Earth.
half moon
A waning moon
quarter moon
The amount of lighted side of the moon you can see is the same during first quarter and third quarter phases. These phases occur when half of the moon's surface is illuminated, and they represent the halfway points between new moon and full moon phases.
The lighted half of the moon is always facing the sun. The entire dark half of the moon is facing earth at the time of "New Moon".
At the phase known as the "new moon" none of the illuminated half of the Moon is visible from Earth.One half of the moon, the side that faces the Sun, is always lighted. But we usually see only part of the lighted side (phases) as the Moon orbits the Earth. When the Moon is directly between the Earth and the Sun (a new moon) none of the lighted side, facing the Sun, is visible from Earth.
After the half-moon phase, the moon's lighted side appears to grow smaller every night, transitioning towards the new moon phase where the moon is not visible in the sky. This progression is known as the waning crescent phase.
That's called the "waxing crescent".
The moon is only visible because of the sun's light, which is why the moon appears to glow. When there is a half moon, only half of the moon is reflecting off the sun's light. It all has to do with the angle of the moon, the sun, and the Earth, which is why the moon has so many different phases.