Answer:
Earth's shadow covering the moon
Earth's orbit and moon's orbit occasionally aligning
Step-by-step explanation:
Solar and Lunar eclipse occur when the Sun, the earth and the moon align in a single line. When sun comes in between the sun and the moon, lunar eclipse occurs and when moon comes in between the sun and the Earth, solar eclipse occurs.
In Solar eclipse, Earth passes through the shadow of the moon. In Lunar eclipse, Moon passes through the shadow of the Earth.