Okay kiddo, have you ever locked your diary with a tiny lock? The Web Cryptography API is kind of like that, but for websites.
When you use a website to buy something or send a message, you want to be sure that nobody can spy on what you're doing or steal your private information. That's where cryptography comes in. It's like a secret code that only you and the website can understand.
The Web Cryptography API helps websites use cryptography to keep your information safe. It's like a big toolbox full of tools that websites can use to make sure your information is encrypted and can't be intercepted by bad guys.
With the Web Cryptography API, websites can create secure keys that only you and they know, encrypt your messages so they can't be read by anyone else, and sign messages so you can be sure they really came from the website and nobody else.
So next time you use a website, remember that they might be using the Web Cryptography API to keep your information safe and secure.