What are the stages of stars life cycle?

SIMPLE EXPLANATION:

Step 1: The dust and gas from a nebula group together.
Step 2: When this group is big enough, energy is created - this group starts to shine.
Step 3: Then it reaches the size of a star.

Step 4: This star becomes a Red Giant - about 500 or more times as big as the Sun now.
Step 5: When the Red Giant runs out of its energy, it explodes as a supernova.
Step 6: This supernova leaves behind a little (50 km across) and dens star - white dwarf.
Step 7: If the Red Giant weighed at least twice as much as our sun, this white dwarf turns into a neutron star and then into a black hole. This whole step occurs in less than a minute.
(Step 8: If a really huge and dens star gets sucked into a black hole, a quasar might have formed)
Note 1: The lifecycle of a star lasts about 10-15 billions of years.
Note 2: Step 8 only may never occur in the lifecycle.