* Low Mass: Red dwarfs are the smallest and least massive stars. They have about 8% to 50% of the mass of our Sun.

* Slow Fusion: Because they are less massive, red dwarfs have lower core temperatures and pressure. This means they fuse hydrogen into helium at a much slower rate.

* Efficient Fuel Use: The slow fusion process makes red dwarfs incredibly fuel-efficient. They burn their hydrogen fuel very slowly, extending their lifespans dramatically.

How long do they live?

Red dwarfs can live for trillions of years, which is many times longer than the current age of the universe!

Comparison:

* Our Sun (a G-type star) has a lifespan of about 10 billion years.

* Larger, more massive stars, like blue giants, have lifespans of only a few million years.

Important Note: Red dwarfs are so faint and cool that it's difficult to study them in detail. However, their long lifespans make them potentially ideal candidates for the development of life, giving planets orbiting them plenty of time to evolve.