A. Lunar Eclipse, the moon passed directly behind the earth and into its shadow, the eclipse happens when the earth’s shadow falls on the full moon
B. Solar Eclipse, the moon passes between the earth and sun-it happens when the moon partially or completely blocks the sun, the eclipse happens when the moon is a new moon
The eclipses don’t happen every month because the earth’s orbit around the sun isn’t in the same plane as the moon’s orbit around the earth.