Well buddy, polyvariance is a big word that means something has many different outcomes or variations, just like when you have different colors of your favorite crayon.
So imagine you are playing a game with your friends and you have a dice with six sides, and you roll it. If the dice has different colors on each side, there can be lots of variations of outcomes or results, just like how your crayons can make lots of different colors. This is called polyvariance.
Or, if you go to a store to buy a toy, but there are lots of different toys to choose from, each with different features and different prices. You might have to consider many different things before you choose one, including how much money you have, how fun the toy looks, and maybe even if it comes with batteries. That's also an example of polyvariance!
So basically, anytime you have to choose between many different options that can lead to different results, that's called polyvariance. It sounds complicated, but it just means there are lots of different possibilities, and you have to make a smart choice.