White dwarf: This is a star that is held up by the pressure of its electrons. Due to the Pauli exclusion principle, the electrons can not all have zero momentum, and must therefore exert pressure.
Chandrasekhar limit: Stars with masses above this limit will overcome the electron pressure and collapse. The limit is 1.4 solar masses.
Supernova: Stars which are significantly above the Chandrasekhar limit may bounce just after they collapse. This blows the surface of the star into space and releases an enormous amount, ~ 1046 J, of energy.
Neutron
star: This is a star which has collapsed, but is
held up by the pressure of compressing the neutrons to
nuclear matter densities. The protons and electrons in a
normal star have converted via the reaction 
.
Black hole: This is formed by a star which is so massive that it collapses to a singularity. Even light is trapped in the interior.