system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do stars, including the sun, shine? What makes the light?
gpt
The light comes from the upper layers of the sun. They shine because they're hot, just like lightbulbs and toasters do. The sun is so bright because at 5500 °C/ 9900 F, the effect is pretty big, and the sun's photosphere is more than 100 kilometers thick, all of which is shining. That adds up. 


You may hear people say stuff about photons from nuclear fusion in the core. ~~Don't believe them.~~ Read their comments with polite skepticism. That is not the light that reaches your eyes.  Underneath the photosphere, the gas doesn't really let any light through. If you are interested in where stars get their energy from, you should read those comments, though.


*Edit: phrasing*