A total solar eclipse occurs when
moon is in the umbral core of earth's shadow.
Earth is in the umbral core of moon's shadow.
earth is in the penumbral core of moon's shadow.
moon is in the penumbral core of earth's shadow
When the moon is in the umbral core of earth's shadow, it is known as total solar eclipse.
If the Moon is in penumbra region of the Earth's shadow then total lunar eclipse occurs.