Why is a sun a star?

Answer 1

the sun has always been a star even before it was called the sun. In fact the sun is a very very small star compared to all the other stars in the universe

Answer 2

The Sun is a star because it is a massive sphere of glowing gas held together by its own gravity. Like other stars, the Sun emits energy through nuclear fusion in its core, producing heat and light. The Sun's proximity to Earth allows it to appear as a bright, shining star in our sky.