The Milky Way galaxy contains several hundred billion stars of various ages, sizes and masses. A star forms when a dense cloud of gas collapses until nuclear reactions begin deep in the interior of the cloud and provide enough energy to halt the collapse.
Many factors influence the rate of evolution, the evolutionary path and the nature of the final remnant. By far the most important of these is the initial mass of the star. This interactive piece illustrates in a general way how stars of different masses evolve and whether the final remnant will be a white dwarf, neutron star, or black hole.
Click link below for an intereactive tour on Stellar Evolution... (also available in pdf form)