What is the relationship and difference between stars and constellations?

Twenty-eight stars are an important theoretical basis for the ancients to infer the good or bad luck of a day.

Twenty-eight hotels originated very early. Originally, it was the 28 groups of stars (or constellations) used by the ancients to observe the running coordinates of the sun, the moon and the five stars. The ancients believed that the positions of the stars were unchangeable, and constellations could be used to explain the positions of the sun, the moon and the five stars. After long-term observation, the ancients chose 28 stars around the equator of the ecliptic as coordinates. Because they revolve around the sun, the moon and the five stars, they are very similar to the places where the sun, the moon and the five stars live, so they are called twenty-eight lodgings. The ancients also divided twenty-eight lodgings into four palaces, east, south, west and north, with seven lodgings in each palace. Each palace imagines its seven dwellings as an animal, and considers it as "the four souls of heaven and square". The seven nights of the East Palace Black Dragon are Jiao, Kang, Bian, Fang, Xin, Wei and Ji; The seven nights that Nangong Suzaku belongs to are: well, ghost, willow, star, Zhang, wing and bird; The seven nights that Xigong White Tiger belongs to are: Kui, Lou, Stomach, Ang, Bi, Gou and Shen; Gong Bei Xuanwu (tortoise and snake) belongs to seven nights: fighting, ox, female, emptiness, danger, house and wall.

Constellation is an indispensable part of astrology and a group of stars in the sky. Since ancient times, human beings have associated three or five stars with their mythical figures or artifacts, which are called "constellations". Constellation is a means to determine the orientation of the sky in almost all civilizations and is widely used in the field of navigation.