Black Hole - Micro and Macro
A black hole is an object with a gravitational field so powerful that it produces a closed curvature of space-time, cutting off that region from the rest of the universe. No matter or radiation can escape the gravitational field, and any energy - including light - that enters the region can ever escape.
Black holes are described by solutions to Einstein's General Relativity equations as developed in 1916. GR theory predicts that when a large enough amount of mass is present in a sufficiently small region of space, all trajectories through space-time are warped inwards toward the center of the volume. GR predicts that following collapse of stars to form a black hole, all the gravitational energy of the mass forms a point-like singularity at the center of the spatial region, and the region is surrounded by an event horizon that nothing can escape.
Black holes can be of almost any mass, so are divided into size categories: Supermassive, containing millions to billions of times the mass of our sun, believed to exist at the center of most galaxies. Intermediate, those black holes whose size is measured in thousands of solar masses. Stellar-mass, holes with masses from about 1.5 to 15 solar masses. And micro black holes, which have masses at which the effects of quantum mechanics are expected to become important.
Black holes proposed to have been formed in the initial Big Bang (primordial black holes) have been proposed, but none have been observed.
Web Resources On Black Hole - Micro and Macro
Quantum Black Holes
Black hole (Wikipedia)
The Black Hole Information Loss Problem
Book Resources On Black Hole - Micro and Macro
Death by Black Hole: And Other Cosmic Quandries by Neil deGrasse Tyson
Black Holes and Baby Universes and Other Essays by Stephen W. Hawking
Origins: Fourteen Billion Years of Cosmic Evolution by Neil deGrasse Tyson and Donald Goldsmith