The event horizon is the boundary surrounding a black hole beyond which nothing, not even light, can escape. This point marks the limit at which the gravitational pull of a black hole becomes so intense that escape is impossible. Once an object crosses the event horizon, it is pulled inexorably toward the singularity at the center of the black hole.
While the event horizon itself cannot be observed directly, scientists study the area around it by examining the behavior of matter and light near black holes. These studies help us understand the extreme conditions around these mysterious cosmic objects.