How do black holes form and what happens if something falls into one?

A black hole is like a cosmic vacuum cleaner that forms when a really heavy star crashes into itself.

Imagine you have a giant balloon full of air, that's like a star. When the star runs out of energy, it can no longer hold itself up against its own gravity. So, it starts to shrink and squish together, squish! If the star is heavy enough, it crushes itself so much that it becomes a super-dense point called a singularity, surrounded by a boundary called the event horizon. That's a black hole!

Let’s say you throw a ball into a black hole, like tossing your favorite toy into a deep, dark well. The ball gets pulled in faster and faster because gravity is super strong near a black hole. It keeps getting squeezed until it disappears from our view, poof! That's what happens to anything that falls into a black hole. It doesn't come back out, but it might make the black hole grow a little bigger.