🌐 How does the internet work?
A network of networks that moves your data in tiny packets.
The internet is a giant web of computers that talk to each other. When you watch a video, your device asks a computer far away (a server) to send it. The video travels in tiny pieces through cables, some of them under the ocean, and your device puts the pieces back together.
The internet is a network of networks: millions of computers, phones and servers linked by fiber-optic cables, Wi-Fi and mobile towers. Every device has an address, called an IP address. When you open a website, your browser first asks a DNS server to turn the name (like wikiwiz.com) into an address, then sends a request to that server. The data comes back in small packets that can take different routes and are reassembled at the end. Shared rules called protocols, like TCP/IP and HTTP, make sure everything speaks the same language.
The internet is a packet-switched interconnection of autonomous systems that exchange reachability with BGP. Hosts are addressed with IPv4 and IPv6; TCP provides reliable, ordered, congestion-controlled streams over IP, while QUIC (the transport of HTTP/3) runs over UDP to cut handshake latency. DNS resolves names hierarchically from the root through TLD and authoritative servers, with caching bounded by TTLs. TLS encrypts most web traffic, and CDNs plus anycast bring content close to users. Physically, submarine fiber cables carry the vast majority of intercontinental traffic.
⚡ Quick facts
- More than 5 billion people use the internet.
- Submarine cables carry most of the data between continents.
- The first ARPANET message, in 1969, was "LO": the system crashed after two letters of "LOGIN".