The ecliptic is the plane of the Earth's orbit around the sun. The ecliptic is also roughly where the moon and all other planets in the Solar system can be found (with the notable exception of Pluto), and it is close to the plane of the galaxy too - when you trace the Milky Way across the sky at night, you're looking along the ecliptic.
The ecliptic is to the orbit of the Earth's year as the equator is to the spin of the Earth's day.