ELI5: Explain Like I'm 5

Compact space

Hey kiddo, have you ever played a game of hide-and-seek? Well, imagine that you're playing this game in a really small room with lots of furniture, like a big closet. You would have to hide in a small space because there's not much room to move around. That's kind of like a compact space in maths.

Now, let's imagine you're playing the same game of hide-and-seek but in a big open field. You have plenty of space to hide and run around. This is like an infinite space, with lots of room to move around and explore.

In maths, a compact space is kind of like the small closet and an infinite space is like the big open field. A compact space is a mathematical concept that refers to spaces that are small and tight, where there's not much room to move around.

But why do mathematicians care about compact spaces? Well, compact spaces have some special properties that make them useful in many areas of maths, especially in calculus and geometry. For example, if you want to study the behavior of functions on a compact space, it's often easier to do so, because you can be sure that the function won't "blow up" or go to infinity in some weird way.

So, in summary, a compact space is a mathematical idea that describes a small and tight space, like a closet, that's useful for studying certain types of functions and problems.