An event horizon refers to a boundary surrounding a black hole, beyond which gravity becomes so intense that nothing, not even light, can escape its pull. Once an object crosses this boundary, it is inexorably drawn into the black hole’s core. This phenomenon results from the extreme curvature of spacetime caused by the black hole’s immense mass. The event horizon marks the point of no return, where the gravitational forces are overpowering, preventing any information or matter from returning to the outside universe. It represents the limit beyond which our understanding of physics breaks down, offering a threshold where the laws of nature, as we currently comprehend them, cease to apply.