Semicolony ELI5 · comic

DNS.

The internet's phone book: it turns a name you can remember into the number a computer needs.

  1. Pizza. Now.
    grr… pizza.com
    1

    You know the name — pizza.com — but computers only call numbers, never names.

  2. …what’s its number?!
    pizza.com ???
    2

    And a name is useless to a computer until it’s turned into an address.

  3. pizza.com — hurry!
    DIRECTORY
    3

    So your computer asks a resolver — the internet’s directory assistance.

  4. flip flip flip root .com pizza .com
    4

    The resolver races down a chain of address books until one of them knows the answer.

  5. Beautiful.
    THE ADDRESS 93.184.216.34
    5

    Back comes the number — the address your computer needed all along.

  6. Next time: instant slice.
    saved! PIZZA
    6

    It connects — and jots the number on a sticky note, so next time skips the whole hunt.

The same lookup that runs, invisibly, before every page you open. (Bit just wants pizza.)
Semicolony semicolony.dev/eli5/dns/comic
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