Simon Griffee · Time, light, movement & distance.

How The Internet Works

4 September 2013 · 1 minute read

Jessica McKellar’s excellent How The Internet Works presentation:


You type into your browser bar and press Enter. What happens?


  1. WHAT is
  2. WHERE is
  3. HOW does my computer talk to
  4. WHAT does my computer SAY to


A format and rules for exchanging information. Internet protocols are layered, one protocol per task. Application-layer protocols that use TCP:


  1. WHAT: DNS for translating hostnames to IP addresses
  2. WHERE: IP for addressing and routing
  3. HOW: TCP for reliable delivery
  4. WHAT do we SAY: HTTP for requesting resources

Address Resolution Protocol (ARP) maps hardware (MAC) addresses to IP addresses. Local network traffic goes through gateway router (usually has IP address and then out to internet.

See also: