The largest black hole

 What is black hole? So many people do not know what is black hole. Black hole is a region of space having a gravitational field. A black hole is a region of space exhibiting such strong gravitational effects that nothing such as light can escape from inside it. The gravity is so strong in a black hole.
The largest black holes are called supermassive. These black holes have masses that are more than 1 million suns together. The black hole or the black hole refers to the space in space, because of the strong gravity of which no object can come out, even the light. Every large galaxy contains a supermassive black hole at its center. Milky way galaxy has a black hole at its center. On December 5, 2011, astronomers discovered the largest supermassive black hole in the nearby universe, with a mass of2.1×10¹⁰ (21 billion) M _☉ at a distance of 336 million light-years away in the Coma Berenices constellation.