How are Private and Public keys generated?

Imagine you have a magic box that can make two special keys that fit only each other. One key is super-secret and you keep it safe, while the other key is like a friendly, open book that anyone can see.

Private Key: First, you pick a number, any number you want, but it's a really big secret number that nobody else knows. This secret number is your private key. It's like your special code that unlocks your magic box. Only you know this code, and you never share it with anyone.

Public Key: Now, the magic box takes your private key and does some cool math with it. It crunches numbers and creates another number that's kind of like a puzzle. This new number is your public key. It's not a secret at all, and you can share it with anyone you want.