Supernovae - stars end their evolution in the catastrophic explosion process.
The term «supernovae» were stars, who witnessed much (in order) stronger than the so-called «new stars». In fact, neither they nor other physically are not new, always break the existing stars. But in a few historical cases erupted those stars that were previously in the sky with little or no visible effect is that of creating a new star. Type of supernova is determined by the presence in the spectrum of the outbreak of the hydrogen lines. If it is, then type II supernova, if not - then I type.