The Different Types of Red Dwarfs

A red dwarf is a star in the sense that it has fusion inside of it. If you don't make it to the threshold of fusion, like if you're like 0.999 below the fusion limit, would you still glow or would you just be like a giant gas planet like Jupiter? You wouldn't have fusion, but you would still be kind of hot. These stars are really fascinating. They tend to radiate in the red region and they're also really, really dim. Like these things are not nearly as bright as our sun.