Many people know the word "astronomy". And most of people also know it is related to stars, sky, and universe. However, they often misread astronomy and mix it with other subjects. Generally speaking, astronomy is often taken as astrology and meteorology.
According to Wikipedia, astronomy is “a natural science that is the study of celestial objects (such as moons, planets, stars, nebulae and galaxies), the physics, chemistry and evolution of such objects, and phenomena that originate outside the atmosphere of Earth, including supernovae explosions, gamma ray bursts, and cosmic background radiation”. Obviously, astronomy focus on the properties of celestial bodies, such as its motion, structure, chemical characters and so on. Additionally, the structure and development of the universe is also contained in the research. Every time there is a sun eclipse or moon eclipse, the experts who appear on the screen to give you exposition are bound to be astronomers. They can tell why the positions of sun, earth and moon in cosmos can form such a phenomenon. Consequently, astronomy is a natural science subject.
Astrology is literally close to astronomy, but the knowledge of them is rather different from each other. The task of experts in astrology is to find the relationships between human society and the positions of certain celestial bodies on the sky in order to make prediction about future. Apparently, astrology is a type of divination. Thus, astrologist won't be insightful in the scientific features of the celestial bodies and won't tell you why sun can be bright for over 4 billion years. Astrology is not in the category of natural science.
As for meteorology, it is a domain in natural science, but not related to astronomy. Such confusion is common in China. In Chinese history, a sage named ZHUGE Liang in Three-State era could predict the weather with astrology. And since then many Chinese have thought ZHU was quite professional in astronomy. Perhaps ZHUGE was good at astrology, but he couldn't be good at astronomy at all. Meteorology is a subject studying the activities in earth atmosphere. The activities of celestial bodies make no difference in weather changes.
Apart from the misinterpretations mentioned above, another subject often mixed is cosmology. Some experts think it a part of astronomy, but other not. It is a subject quite similar to astronomy. But the difference is: Cosmology concentrates on the whole universe, especially on its large-scale structure.