ELI5: Explain Like I'm 5

Topological abelian group

Okay kiddo, imagine you have a bunch of toys, but some of them are connected to each other by strings. Now, imagine you want to move the toys around, but you can only move them by pulling on the strings that connect them.

A topological abelian group is kind of like those toys connected by strings, but instead of toys, it's a group of numbers that can be added together (we call it an "abelian group" because the addition is commutative - meaning order doesn't matter). But the twist is that we've also given each number a special "location" in a space (we call it a "topology"), kind of like how the toys are in different places in your room.

Now, just like how you can only move the toys by pulling on the strings, with a topological abelian group, we can only add the numbers together if they are in "close" locations. And what counts as "close" is determined by the topology.

So in summary, a topological abelian group is a group of numbers that can be added together, but only if they are "close" to each other in a certain space. Just like how you can only move toys by pulling on strings that connect them.