ELI5: Explain Like I'm 5

Category of topological spaces with base point

Imagine you have a bunch of shapes, like circles, squares, and triangles. Now imagine that you want to study these shapes and figure out how they are related to each other. This is kind of like trying to figure out how cats, dogs, and birds are related to each other because they are all animals.

But just looking at shapes or animals by themselves isn't enough. You also need to look at where they are and how they are positioned. For example, a circle could be big or small, and it could be in the middle of a room or on the edge of a table. This is like how a cat could be in a living room or outside, and it could be sitting on a couch or a chair.

So really, what you want to study is not just the shapes or animals, but the shapes or animals in certain places or positions. This is where topological spaces with base points come in.

A topological space is just a fancy way of saying a place where shapes can exist and be studied. And a base point is a special point in that place that is used as a starting point for studying the shapes.

Think of it like going on a treasure hunt. The topological space is the general area where you'll be searching for treasure, and the base point is the spot where you'll start looking.

Why is this important? Well, by focusing on a specific topological space with a base point, you can start to understand how shapes are related to each other in that particular space. You can also start to understand how moving the base point changes the relationships between shapes.

For example, imagine you have a circle in a certain topological space with a base point. If you move the base point around, the circle might appear to move or change shape based on its position relative to the base point. By studying these changes, you can learn more about both the circle and the topological space it's in.

So in summary, a category of topological spaces with base point is a way of studying shapes in specific places, using a specific spot as a starting point for that study. By doing this, we can learn more about both the shapes and the places they exist in.