ELI5: Explain Like I'm 5

Character theory

Character theory is like a big puzzle game for numbers, but instead of using puzzle pieces and colors, we use lots of numbers and some fancy math tools. We have different types of characters, and each character has a set of rules that tell us how to combine them to form a bigger group.

So, let's say we have three puppies, and we want to know how many ways we can arrange them in a line. We could start by writing out all the possibilities, but that would take a long time. Instead, we can use character theory to make it faster.

We assign each puppy a symbol or character – let's use A, B, and C. Then we can use our fancy math tools to figure out how many ways we can arrange these characters.

Each character has a set of rules that tell us how it behaves when we multiply or combine it with another character. For example, A might act differently from B, and B might behave differently from C. We use these rules to group the characters together, and then we can use some more math tools to count how many different groupings there are.

Once we've done that, we can then figure out how many ways we can arrange the real puppies in the line. And we did it quickly and easily thanks to character theory!