The similarity is that in both phases, the moon is only ¼ lit.
The moon has four phases, which happen in a fixed sequence. Each phase lasts one week and takes place as follows:
1st week - New Moon: At this moment, the part of the moon that is illuminated by the sun is not facing the earth. This prevents the moon from being seen.
2nd week - Crescent Moon: Only ¼ of the moon is being lit by the sun and facing the earth. Therefore, we can only visualize a small part of the moon.
3rd week - Full Moon: The face of the moon that is facing the earth is completely illuminated by the sun, which allows this entire face to be visualized.
4th week - Waning moon: Once again, only ¼ of the moon is lit by the sun and facing towards the earth.
The moon does not have its own light, but reflects the light received by the sun, for this reason, we cannot fully visualize the moon.
