Can anyone explain me what a blackhole is.
A black hole is a region of space from which nothing, not even light, can escape or we can say these are formed when the gravitational pull of a star exceeds to such a high limit that not even light can escape from it. Black holes exist in space and are last phase of giant stars. It is supposed to form this when the fission reaction is absolutely complete.
A black hole is a region of spacetime where gravity prevents anything, including light, from escaping. The theory of general relativitypredicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called anevent horizon that marks the point of no return. It is called "black" because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body inthermodynamics. Quantum mechanicspredicts that black holes emit radiation like a black body with a finite temperature. This temperature is inversely proportional to the mass of the black hole, making it difficult to observe this radiation for black holes of stellar mass or greater.