How is a star's brightness described?

Venus is the brightest star. It is also the hottest planet it reflects a lot of light from the sun and we can see it as a bright dot in the sky.

Also known as it's magnitude. The apparent magnitude is how bright it looks from the earth, while the absolute magnitude is how bright the star would be from a set distance.

tfrdtfygfjyuftgyfsdtredashgesrfdhgt

they are described by hot gasses

That is called the apparent magnitude. The absolute magnitude, on the other hand, indicates how bright a star would look, from a standard distance of 10 parsecs.