Azimuth is a function of the observer's location. Or to put it another way, it is a line through the sky directly above the Earth's equator. If you were standing on the Earth's equator, the CE would run from due East to due West, passing directly overhead. To an observer at the North or South Pole, the CE runs along the horizon. From ancient times, the supposed spherical shell surrounding the Earth and containing all the stars, planets, the Sun, and the Moon.
Declination is the distance, in degrees, away from the celestial equator.
Positive values indicate the object is north of the celestial equator, negative values indicate the object is south of the celestial equator. Declination is independent of the observer's location. An eclipse occurs when the Earth, Moon, and Sun are lined up such that either the Earth or the Moon casts its shadow on the other body. The Earth passes between the Moon and Sun, and its shadow darkens the Moon. The Moon passes between the Earth and Sun, blocking out the Sun.