Okay kiddo, have you ever written a letter to someone? You know, like where you write down what you want to say on a piece of paper and put it in an envelope and send it to them in the mail?
Well, email is kind of like that but it's electronic. That means you use a computer, tablet, or phone to write your message instead of using a pen and paper.
When you send an email, it doesn't go through the regular mail service. Instead, it gets sent over the internet. Think of the internet as a big network of computers that can all talk to each other. When you hit "send" on your email, it goes from your computer to a server (which is like a big computer that's always online and ready to receive messages) and then to the recipient's computer.
And just like a regular letter, you can send attachments with your email too. Those can be things like pictures, videos, or even documents that you need to share with someone.
Overall, email is a really convenient way to communicate with people who aren't nearby or even in the same country as you. Plus, it's pretty fast - you can usually send and receive emails within a few minutes!