Question

difference between redgiant and hypergiant and how r they formed

Answer 1

blue giant:A blue giant star is a swelling middle-aged star that is running out of hydrogen to burn but hasn’t started burning helium. It is blue because it burns hotter as it begins using the remaining hydrogen. After a few million years, these type of starts will begin to burn helium and swell up further.
red giant:Once a star nears the end of its life, it must resort to burning helium. Helium is heavier than hydrogen, and burning it causes the star to expand greatly in size and become a red giant.

the differences between a blue giant and a red giant are the age of the stars and their permanence. No blue giant remains a blue giant; it eventually will turn into a red giant.

Hope this is it...