Zodiacal Constellations

In astronomy, the zodiac (Greek: ζῳδιακός, zōdiakos) is the ring of constellations that lines the ecliptic, which is the apparent path of the Sun across the celestial sphere over the course of the year. The paths of the Moon and planets also lie roughly within the ecliptic, and so are also within the constellations of the zodiac. In astrology, the zodiac denotes those signs that divide the ecliptic into twelve equal zones of celestial longitude

celestial sphere- In astronomy and navigation, the celestial sphere is an imaginary sphere of arbitrarily large radius, concentric with the Earth and rotating upon the same axis. Here is a link of a celestial sphere
http://en.wikipedia.org/wiki/File:Celestial_sphere.svg

celestial longitute- The ecliptic coordinate system is a celestial coordinate system that uses the ecliptic for its fundamental plane. The ecliptic is the path that the sun appears to follow across the sky over the course of a year.

information from Wikipedia
http://en.wikipedia.org/wiki/Zodiacal_Constellations
link is above