Final answer:
An eclipse is an astronomical event where one celestial body passes through the shadow of another celestial body. A lunar eclipse happens when the Moon moves into the Earth's shadow during a full moon, while a solar eclipse occurs when the Moon blocks the Sun's light.
Step-by-step explanation:
An eclipse is an astronomical event that occurs when one celestial body passes through the shadow of another celestial body. In the case of a lunar eclipse, the Moon moves into the shadow of the Earth, and this can only happen during a full moon. On the other hand, a solar eclipse occurs when the Moon passes in front of the Sun, blocking its light.