I want to see some pictures of constellations.

Celestial sphere: it is a very large sphere, extending infinitely from the center of the earth's sphere. As you can imagine, the earth is a very small core inside the celestial sphere. It is an imaginary rotating sphere, corresponding to the earth, and it also has its equator (celestial equator). The celestial equator divides the celestial sphere into two parts: the northern hemisphere and the southern hemisphere. Corresponding to the Tropic of Cancer, Tropic of Capricorn, South Pole and North Pole.

celestial map

Celestial equator: a great circle that extends infinitely to the equatorial plane of the earth and intersects the celestial sphere. It is similar to the equator of the earth, but much larger than it.

Right ascension? Declination, these two concepts are the same as latitude and longitude on the earth.

Ecliptic? That is, the annual apparent trajectory of the sun on the celestial sphere, that is, the great circle of the sun's apparent trajectory in the sky, is called the "ecliptic", that is, the projection of the earth's orbital plane on the celestial sphere.

Zodiac map

White road? The great circle and white road map of the moon's orbit around the earth intersecting the celestial sphere.