How do the main sequence stages of a 1 solar mass star and a 15 solar mass star differ?

Stellar evolution is the process by which a star undergoes a sequence of radical changes during its lifetime. Depending on the mass of the star, this lifetime ranges from only a few million years (for the most massive) to trillions of years (for the less massive), considerably more than the age of the universe. ^

Small, relatively cold, low mass red dwarfs burn hydrogen slowly and will burn for hundreds of billions of years

Massive hot supergiants will live for just a few million years.

A mid-sized star like the Sun will remain on the main sequence for about 10 billion years.