Albert Einstein first predicted black holes in 1916 within his general theory of relativity. The term "black hole" was invented in 1967 by American astronomer John Wheeler, and the first black hole was discovered in 1971.
Black holes are formed when the centre of big a star becomes unbalanced with the amount of hydrogen and helium atoms in this case acts like radiation pushing against gravity, when the star becomes unstable it starts to produce iron which doesn't generate any energy, which causes iron to build up in the centre off the star and cause a supernova
After a supernova occurs it takes less than a 1 second to activate a stellar black hole, moving at around a quarter of the speed of light
There is no current proof that there is more than one type of blackholes, but there is many theories around three different types of blackholes. Stellar, Supermassive, and Miniature.
it has been proven for miniature black hole to burn out very quickly, in another case if the black whole had the same mass or more than the sun it would take 10>67 years to evaporate which equals to 1 followed by 67 zeros.
Spagettification is one of the many deadly factors of a black hole to a human, it is the explanation to what happens to your body after it enters in theory rips and tear your body up with your unconscious using gravitational force