First we need to know about Black hole. It is a Region of Space-time which exhibits such gravitational force that nothing can pass through it.Despite its invisible interior, the presence of a black hole can be inferred through its interaction with other matter and with electromagnetic radiation such as visible light. The calculations by the scientists had predicted that it might have the same density as the Sun. Gravity effects light and nothing can travel faster than the light. So, inside black hole, the gravity is dense and time slows near black hole.
The basic principle is that because of the curvature of space time around a black hole, the amount of "distance" a beam of light has to cover is greater near a black hole. However, to an observer in that gravitational field, light must appear to always be 300,000 km/sec, time has to slow down for that individual as compared to someone outside that gravitational field as related by the time/distance relationship of speed. A black hole has a boundary called event horizon. Light gets trapped inside the event horizon.Nothing can travel faster than light, everything else will get dragged back inside the black hole.
If we fall inside the black hole, the only way to escape from there is to travel faster than the speed of light. In this Universe, nothing can travel faster than the speed of light, so you can never escape from the Black hole.
