BLACK HOLE
A black hole is a super dense singularity where gravity is so extreme that nothing can escape, not even light. The singularity is surrounded by an accretion disk of super-heated matter that feeds the black hole; while the black hole itself is not visible, accretion discs are among the brightest objects in the universe. The black hole's event horizon is a boundary that serves as the point of no return; anything that crosses this threshold is on a one-way trip to oblivion. Black holes are formed when a very massive star collapses at the end of its life cycle.
CLASS C: CHARGED
A charged black hole is a black hole (either rotating or non-rotating) with an electrical charge and a second event horizon. Known as the Cauchy horizon, this inner event horizon marks the threshold where reality itself breaks down. Cause no longer precedes effect, the past has no bearing on the future, and time travel may be possible.
CLASS K: KUGELBLITZ
A Kugelblitz is a black hole formed from radiation instead of matter. If enough radiation is aimed into a region, the concentration of energy can warp the space-time continuum enough for the region to become a black hole. At that point, it would have functions identical a conventional black hole.
CLASS R: ROTATING
A rotating black hole is formed in the collapse of a massive spinning star or the collapse or collision of stellar bodies with some degree of angular momentum. Most black holes are of this variety.
CLASS S: SCHWARZCHILD
A non-rotating black hole with no electrical charge. These typically do not form in nature, but rotating black holes that produce large amounts of energy at the expense of their rotational energy may transition into a Schwarzchild.
CLASS V: VIRTUAL
A virtual black hole is one that exists temporarily as a result of minute quantum fluctuations in the space-time continuum. Unlike their brethren, these black holes are microscopic and evaporate within moments of formation.
Black holes are further divided into subclasses based upon mass.
SUBCLASS 1: PRIMORDIAL
A very low-mass black hole that is only associated with Class V. As such, all virtual wormholes are regarded as Class V1.
SUBCLASS 2: STELLAR MASS
A black hole with a mass between 4 and 15 solar masses, commonly associated with singularities that result from the core-collapse of a supermassive star.
SUBCLASS 3: INTERMEDIATE
A rare black hole with a mass of approximately 1,000 solar masses that is formed within clusters of supermassive stars and may eventually evolve into a supermassive black hole.
SUBCLASS 4: SUPERMASSIVE
The largest variety of black hole, with a mass between one million and one billion solar masses. They are found in the center of almost every large galaxy.