What is a network?
A network is just computers connected together so they can send each other messages. Two phones, a printer and a laptop, or a billion machines spread across the planet — same idea at every size. Once two computers can pass a message back and forth, you have a network. The internet is simply the biggest one: a network of networks.
A network is computers that can message each other
Imagine a few computers in a room, each with a wire running to one little box in the middle (a switch). That box's only job is to pass messages between whatever's plugged into it. Now the laptop can talk to the printer, the phone can talk to the laptop. That's a network — nothing more. The wires can be cables or invisible (Wi-Fi is just messages sent as radio waves instead of down a cable). What matters isn't the wire — it's that a message can get from one machine to another.
Small networks join into bigger ones — that's the internet
Your home has a small network (your phone, laptop, TV, all talking to your router). Your school or office has its own. A coffee shop has one. On their own, each is an island. The magic is connecting the islands. Your home network connects to your internet provider's network, which connects to others, which connect to others… all the way around the world. 'The internet' is literally that: a network OF networks, so a message from your phone can reach a server on the other side of the planet by hopping island to island.
Every machine needs an address, and a message gets cut into packets
For a message to reach the right machine, each computer needs a unique address — like a house number. On a network that's its IP address (the next topic). You write the destination address on your message and the network figures out how to deliver it. And a message rarely travels as one big lump. It gets chopped into small chunks called packets, each labelled with the destination, sent separately, and reassembled at the other end. That's why a hiccup mid-download doesn't lose everything — only the missing packets get re-sent. We'll watch a packet make this journey later.
Questions you might have
▸Is the internet one giant computer somewhere?
No — there's no single 'internet machine.' The internet is millions of separate networks (homes, companies, data centers) all connected so their computers can message each other. It's a web of connections, not a place.
▸What's the difference between the internet and Wi-Fi?
Wi-Fi is just one way to connect to a network without a cable — radio waves between your device and a nearby router. The internet is the giant worldwide network you reach THROUGH that router. Wi-Fi is the last little hop; the internet is everything beyond it.
▸How does a message know which computer to go to?
Every machine on a network has a unique address (its IP address). Your message is labelled with the destination address, and the network passes it along — switch to router to router — until it reaches the machine with that address. Just like mail finds a house by its number and street.
▸Why cut a message into packets instead of sending it whole?
Lots of reasons: small chunks share the wires fairly (nobody hogs the line with one huge file), they can take different routes, and if one chunk gets lost only that little piece is re-sent — not the whole thing. Packets make the network resilient and fair.