Imagine that you have a bunch of different types of candies in a bag, like skittles, M&Ms, gummies, and chocolate bars. Now imagine you want to mix them up in certain proportions to make a new candy flavor. For example, you might want to mix 70% skittles, 20% M&Ms, and 10% gummies to make a new candy flavor.
The CKM matrix is kind of like a recipe for mixing different flavors of particles in the universe called quarks. Just like with candies, there are different types of quarks, including up, down, charm, strange, top, and bottom. And just like with the candy example, there are certain proportions you need to mix them in to create different particles.
The CKM matrix tells scientists how much of one type of quark needs to mix with another type of quark to create a certain particle. It's like a big chart that helps scientists predict what particles will form when quarks combine in different ways. This is important because it helps us understand how the universe works and how it was created.