Every object in the universe distorts what Einstein called ‘spacetime’. If you stretch out a sheet until its taut it’s perfectly flat. Put a marble on it and the marble makes a small depression in the fabric around it. Put a bowling ball on the sheet and the depression and its effects are much much more noticeable than the marble. We call these depressions gravity wells.
Each gravity well has a specific speed needed to escape it. The speed needed to escape from the bowling ball’s depression is much greater than the speed needed than the marble.
Now imagine the bowling ball is the Sun. Photons leaving the sun have more speed than what is needed to escape the sun’s gravity well.
Now imagine you drop a wrecking ball onto the sheet, and the depression it creates is huge. That might be like a black hole, where the speed needed to escape it’s gravity well[1] is much more than even photons have.
[1] This is a wildly over simplification, but it works well enough for ELI5.
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