Answer:
Supergiant stars are the largest stars, and they are much larger than our own Sun. Some of them are thousands of times bigger than the Sun. Betelgeuse, which happens to be the 9th brightest star in the sky, is much larger than our Sun. The radius of this star is up to 1200 times than of our sun.
The red dwarf stars are considered the smallest stars known, and representative of the smallest star possible. Brown dwarfs are not massive enough to build up the pressure in the central regions to allow nuclear fusion of hydrogen into helium.
Step-by-step explanation: