According to the No-Hair Theorem, a black hole has the interesting property that all information and structure that falls into a black hole becomes trapped from the rest of the universe, and perhaps even destroyed, except for its effect on the total mass, charge, and angular momentum of the black hole. The overall mass of a black hole is what determines the strength of its gravity. When scientists talk about large or small black holes, they are actually talking about the mass of the black hole. Large black holes have more mass, more gravity, and therefore more effect on their surroundings. When matter falls into a black hole, it increases the overall mass of the black hole. The overall electric charge of a black hole determines the strength of the electric field that it creates. When matter with electric charge of the same polarity as the black hole falls in, it increases the charge of the black hole. The overall angular momentum of a black hole describes how fast it is spinning. When matter falls into a black hole with a swirling motion (as opposed to falling straight in), it can increase the black hole's total angular momentum if the matter swirls in the same direction, or decrease the black hole's total angular momentum if it swirls in the opposite direction. We don't know exactly what goes on in a black hole. The matter inside a black hole could be condensed down to an indistinguishable blob. Or the matter could retain some structure but remain trapped in the black hole by the black hole's intense gravity. The problem is that a black hole's center is so small that the theory of General Relativity, which describes gravitational effects, becomes inaccurate. We need quantum theory to accurately describe physics on the very small scale. But we have not yet developed a correct theory of quantum gravity. Therefore, we won't have a good idea of what goes on inside a black hole until we have an accurate theory of quantum gravity. The fact that the inside of black holes is shielded from all experimental observations makes the task even more difficult. Source: wtamu.edu by Sir Christopher S Baird......