# What is Event Horizon of a Black Hole? [closed]

The boundary of a black hole is said to be surrounded by event horizon - the point of no return! What is its significance in terms of general relativity?

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## closed as too broad by called2voyage♦Mar 10 at 18:38

There are either too many possible answers, or good answers would be too long for this format. Please add details to narrow the answer set or to isolate an issue that can be answered in a few paragraphs.If this question can be reworded to fit the rules in the help center, please edit the question.

The question "What is its significance in terms of general relativity?" is both too broad and out of scope for this site (belongs on Physics.SE). Could you clarify exactly what information you are looking for? –  called2voyage Feb 25 at 17:28
What I mean to say is, how are the characteristics of event horizon related to Space-Time? –  Spacetrekker Feb 26 at 13:45

It is exactly the point of no return for light. In other words, it is the point (actually more like a sphere) in which the escape velocity from the Black Hole gravity reaches $c$.

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