Solar Eclipse: When the Moon comes between Sun and Earth, it's shadow is cast on to some parts of the Earth. This is called a Solar Eclipse. It always takes place on a New Moon Day.
Lunar Eclipse: When the Earth comes between Sun and Moon, it's shadow falls on the moon. Because of this, the moon becomes invisible at night and then it slowly appears back. This is called a Lunar Eclipse. It always takes place on a Full Moon Day.