Video narration
How can a star become a place even light cannot escape? Think of a tug-of-war: fusion in a star's core helps create pressure pushing outward, while gravity pulls inward. When those forces balance, the star holds up. When fusion can no longer support the core, that balance fails. This doesn't mean fusion everywhere in the star suddenly switches off. Gravity hasn't suddenly appeared; the core simply can't resist its pull. If the remaining core is massive enough, collapse continues. Not every dying star becomes a black hole; it depends on the mass left at the center. An event horizon is the boundary beyond which light cannot escape. It isn't a solid surface or a cosmic vacuum cleaner sucking in everything nearby. So a star doesn't vanish: its sufficiently massive core collapses until an event horizon forms, trapping even light. That's a black hole.