ELI5: Explain Like I'm 5

Localization of a ring and a module

Okay kiddo, so let's imagine that we have a big circle, like a donut. This donut is called a ring. Now, this ring can have different parts, like a top part, a bottom part, a middle part, and so on. Each part has its own special name, like "ideal" or "maximal ideal".

When we want to talk about just one part of the ring, we can "localize" it. This means we zoom in on just that one part and focus on it by imagining that it's the whole ring. For example, we might want to look at just the top part of the ring and ignore everything else.

Now, let's talk about a module. A module is like a group of things (called "elements") that are organized in a special way. It's kind of like a bunch of legos that are put together in a certain order to make something cool, like a spaceship or a castle.

When we talk about localizing a module, we're doing something similar to what we did with the ring. We're zooming in on just one part of the module and focusing on it. We might want to look at just one set of legos that are put together in a certain way and ignore all the other legos.

Overall, localization is a way of looking at just one part of something and ignoring everything else for a short time. This can be helpful when we're trying to study a specific aspect of a bigger thing, like a ring or a module.