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computing-networking

How Wi-Fi Works

Wi-Fi is a short invisible bridge between your device and a nearby network.

Think of two people using walkie-talkies: they turn words into radio waves, share one channel, and take turns so both messages can be heard.

  1. A message on a phone changing into a row of digital ones and zeros.createsAppDigital bits

    Step 1

    Your app makes digital data

    A photo, message, or web request begins as bits inside your phone or computer.

  2. Digital bits paired with changing radio waves sent by a Wi-Fi chip.Words in awalkie-talkie=Bits in a radiosignal

    Step 2

    Wi-Fi puts bits on radio

    The Wi-Fi chip represents those bits by carefully changing a radio signal.

  3. Radio waves moving from a laptop to a nearby wireless access point.Your deviceRadio signalAccess point

    Step 3

    An access point listens

    A nearby access point receives the radio signal and recovers the digital data.

  4. A router forwarding an addressed packet from the local network toward the internet.packetforwardLocal Wi-FiRouterOther networks

    Step 4

    The router sends packets onward

    The router reads each packet's destination and forwards it toward the right network.

  5. Reply data flowing from other networks through a router and access point to a phone.replyradioOther networkRouterYour device

    Step 5

    A reply finds its way back

    Reply packets reach the router, and the access point sends their data to your device by radio.

  6. Several devices taking turns to use one shared Wi-Fi radio channel.Quiet channelFew devicesShort waitsCrowded channelMany devicesMore waiting

    Step 6

    Nearby devices share airtime

    Devices using one Wi-Fi channel coordinate their turns. Crowded channels can make everyone wait longer.

Common trap

Wi-Fi and the internet are the same thing.

Wi-Fi is usually the local radio connection to an access point. The router then connects that local network to other networks.

Quick check

What carries data between your phone and a Wi-Fi access point?

  1. Radio waves
  2. A hidden cable
  3. Sound waves
Show the answer

The Wi-Fi chip encodes digital data onto radio waves for the nearby access point.

Sources

  1. What Is Wi-Fi?Cisco
  2. Guidelines for Securing Wireless Local Area NetworksNational Institute of Standards and Technology
  3. What is a router?Cloudflare Learning Center