SHA-2 is like a secret code that computers use to keep information safe.
Have you ever played a game where you had to keep a secret message from someone else? Maybe you wrote the message in a code that only you and your friends could understand. SHA-2 is a code like that, but way more complicated!
When you send emails or messages online, your computer transfers it from one computer to another until it reaches the person you're sending it to. This means that people who are not supposed to see your message could get access to it. To stop this from happening, your computer can use SHA-2 to turn your message into a secret code that no one else can understand unless they have the key to unlock it.
SHA-2 uses a math formula to change your message in a way that makes it impossible to figure out the original message unless you have the right key. The key is like a special word that only the person you want to share the message with knows.
SHA-2 is so strong that it's virtually impossible for anyone to break the code and read your message without the key. So now you can send messages, emails, and even pay for things online knowing that your information stays safe and secure.