the.com/ecliptic plane

means The imaginary flat surface traced by Earth's orbit around the Sun, which most other planets roughly share — the reason the solar system is shaped more like a disc than a sphere.

from From Greek 'ekleiptikos' (relating to an eclipse), via Latin 'ecliptica.' The name comes from the fact that eclipses only happen when the Moon crosses this very plane — ancient astronomers mapped the line in the sky where Sun, Moon, and Earth occasionally line up, and named it after the dramatic event that gave it away, long before anyone understood orbital mechanics.