When you use your phone or any kind of device to connect to the internet, your device has a special number called a subscriber identification that helps the internet know who you are. Think of it like having your own nametag that tells people who you are in a crowded room.
Now, when you want to do something on the internet like send a message or stream a video, your device needs to tell the internet who you are and which nametag belongs to you. This is called transmitting your subscriber identification.
So, your device sends a message to the internet with your nametag information in it. Just like if you wanted to talk to your friend in a noisy room, you would need to go close to them and talk louder, right? Well, your device sends this message loud and clear to the internet so it knows who you are and can send you the information you want.
This is how the internet knows who you are and helps you get the stuff you want. Now, isn't that cool?