ELI5: Explain Like I'm 5

Manifolds

Okay, so a manifold is like a special kind of surface or shape that can change shape and curve around without breaking or tearing. It's like a rubber sheet that you can bend and stretch in different ways, but it always stays nice and smooth.

Now, imagine that the rubber sheet has a bunch of dots or points on it. These dots are called "points" in math language. And imagine that each of these dots has a special set of directions you can move in, kind of like a compass. This set of directions is called a "tangent space."

So on a manifold, each point has its own little tangent space that tells you how you can move and bend around in that specific spot without breaking the rubber sheet. And the entire manifold is made up of all of these little tangent spaces for all of the points.

Now, why do we care about manifolds? Well, we can use them to study all sorts of things in math and science, like how things move and change over time. We can also use them to describe the shape of things like the surface of the Earth or the human brain, which are both kind of like manifolds in their own way.

So, to sum up: a manifold is a special kind of rubber sheet that can bend and stretch without breaking, and each point on the sheet has its own set of directions you can move in called a "tangent space." We can use manifolds to study all sorts of cool things in math and science, and to describe the shape of things in the world around us.