World 4 · What Happens When You Type a URL · 12 min · PRO
DNS records
A, AAAA, CNAME, MX and friends
PRO · How the Internet Works
World 4: What Happens When You Type a URL is part of PRO
The first world of How the Internet Works is free. PRO opens the other 26 lessons in 6 worlds — simulations, quizzes and all.
PRO includes
- All 60 labs — every world, every lesson
- Practice exams and certificates
$8.33/mo, billed yearly ($99.99) · or $39.99 monthly