A star is a spherical cluster of gases held by the force of their own GRAVITATION. Stars spreads electromagnetic radiation since they accumulate huge NUCLEAR ENERGY, mainly due to the conversion of hydrogen into helium. All the stars that can be seen from the Earth with the naked eye, are part of the Milky Way. In addition, a star has different kinds of names such as a red-hot and luminous celestial body.
Of course the famous and the closest star is the Sun. That is why it seems to us that it is very large in comparison with other luminaries in space. In the daytime it eclipses all other stars, so we do not see them. If the Sun is 150 million kilometers away from the Earth, then the other star, which is closest to the rest, Centaurus, is already 42,000 billion kilometers from us. The heaven bodies are different in their size and intensity of light emission.
The sun is the only star in the solar system. It is a red-hot gas clot and it is really bigger than planets. Also, the sun exceeds all the planets of the solar system and 330 thousand times the mass of the Earth.