ELI5: Explain Like I'm 5

Dagger compact category

So, you know how sometimes you need something tiny and compact, like a small toy or a snack you can easily carry in your pocket? The dagger compact category is kind of like that!

But instead of toys or snacks, we're talking about something called a "category." A category is like a big group of things that are all kind of similar in some way. For example, you might have a category of fruits, with apples and bananas and oranges and things like that.

Now, the dagger compact part is a special way of looking at these categories. It has to do with how you can combine things from the category together, kind of like how you might combine different toys to make a new game.

The dagger part means that we're allowed to have special things called "maps" that go from one thing in the category to another thing. It's like having a little arrow that shows you how to get from one toy to another.

The compact part means that we're also allowed to "smush" things together in certain ways. You know how you can press down on a toy and make it smaller or flatter? We can do something similar with the things in the category, to make them easier to work with.

So basically, the dagger compact category is a way of looking at a big group of things (like fruits or toys) and figuring out how we can combine them together in certain special ways. It's kind of like a fun game that mathematicians play!