How can a star be so bright yet have such a low surface temperature?

The star is bright, cool, and red.How can a star be so bright yet have such a low surface temperature?Surface area. Imagine you have a glow stick the size of a nickel. You will not be able to see it a mile away, but if it was the same brightness, but many, many times bigger, say 500 feet across, you would be able to see it.