Is the Sun a star?
user
Well, it is actually a star and also a planet, so technically it is both a star and a planet at the same time!
assistant
I did not know that it is a star and also a planet.
user
Sure, people use the term “sun” for both the star and the planet.
assistant
What is it made of?
user
It is mostly hydrogen and helium gas.  In fact it would be mostly empty space without its heavy elements.  By the way, what do you think the word “star” means?
assistant
Is the Sun a star?
user
Well, it is actually a star and also a planet, so technically it is both a star and a planet at the same time!
assistant
I did not know that it is a star and also a planet.
user
Sure, people use the term “sun” for both the star and the planet.
assistant
What is it made of?
user
The sun is mostly made of hydrogen and helium, which are the simplest and lightest elements.
assistant
Is the Sun a star?