Why does my message get cut into tiny pieces to travel?

Think of the soft whoosh your tablet makes when you send a message to someone you love. In a blink, your words leave your hands and fly off to Grandma's tablet far away.

Yet your message does not travel in one big piece. It travels as lots of tiny pieces. So why does your message get cut into tiny pieces to travel?

When you tap send, your tablet chops your message into small pieces called packets, which means little bundles that each carry Grandma's address. That address shows every packet where to go.

Your tablet also gives each packet a number, like number one, number two, and so on. Those numbers will help Grandma's tablet put the words back in the right order at the end.

Now the packets zoom out through the air and along long wires. Those same wires carry messages, videos and calls from lots of people at the very same moment.

If your whole message went as one giant piece, it would block the wire, like a long train stopping all the cars at a crossing. Small packets take turns with everyone else's packets, so all the messages keep moving.

Your packets hop from stop to stop across the city, each one finding its own path toward Grandma. The trip is long, and a packet can get lost along the way. What do you think happens if one little packet goes missing?

Grandma's tablet checks the numbers and notices that one is missing. It asks your tablet for just that one packet, and only that tiny piece travels again, not the whole message. That is much quicker than starting over.

Then Grandma's tablet lines up all the packets by their numbers. Your words join back together, and your whole message pops up on her screen.

Your tablet cuts your message into small packets so they can take turns with everyone else's packets on the wires that all of us share. And if one packet gets lost, your tablet sends just that one again instead of the whole message.

Far away, Grandma reads your words and smiles. All those tiny packets made the long trip, and now they sit together again, every one in its right place.