What exactly is the event horizon of a black hole?

I've never been sure of the answer. Is the event horizon different for different things with different speeds? For example, the event horizon for an object with 5 G's of acceleration is closer in than an object with only 2 G's of acceleration.



Or is the event horizon a fixed point (depending on the mass of the Black Hole) that is the true point of no return from which even light cannot escape?



None of the science documentaries ever says for certain.What exactly is the event horizon of a black hole?
Event horizon is define as the point of NO return, a surface covering the black hole beyond which no kind of information from the inside is able to escape. This includes light. Hence if you look at the black hole from infinity, you will see the black surface as the actual even horizon. However, if we keep moving towards it, the black surface will also appear to become smaller. Hence one cannot actually know if he/she has crossed the even horizon.What exactly is the event horizon of a black hole?
"Or is the event horizon a fixed point (depending on the mass of the Black Hole) that is the true point of no return from which even light cannot escape?"



It's that.What exactly is the event horizon of a black hole?
It's the point where the escape velocity equals the speed of light, allowing for the rotation and mass of the black hole.