Okay kiddo, imagine you're at home and you want to go outside to play, but you're not sure which door to use. You could ask your mom or dad which door to use, or you could try to figure it out on your own.
Now imagine you're using a computer to go on the internet, and you want to visit a website. Your computer needs to know which way to go to get to that website. Sometimes, your computer can figure it out on its own, but sometimes it needs a little help.
That's where the web proxy autodiscovery protocol comes in. It's a fancy name for a way that your computer can figure out how to get to websites without you having to tell it every time.
Think of it like a treasure map. The map shows you where the treasure is, but you still have to follow the clues to find it. In the same way, the web proxy autodiscovery protocol gives your computer a map that shows it where to find the website. But it still has to follow the clues to get there.
Basically, when you tell your computer to go to a website, it checks to see if there's a map available that tells it how to get there. If there is, it uses the map to get to the website. If there isn't, it might ask someone (like your mom or dad) for help, or it might try to figure it out on its own.
And that's the web proxy autodiscovery protocol explained like you're five!