The third book in the Astronomy and Astrophysics series contains an overview of modern ideas about stars. It tells about the names of constellations and the names of stars, about the possibility of observing them at night and during the day, about the main characteristics of stars and their classification. The main attention is paid to the nature of stars: their internal structure, energy sources, origin and evolution. The late stages of stellar evolution are discussed, leading to the formation of planetary nebulae, white dwarfs, neutron stars, as well as novae and supernova explosions. The book is aimed at junior students of university natural science departments and specialists in related fields of science. The book is of particular interest to astronomy lovers..