DNS

The phonebook of sorts that makes this happen is called the Domain Name System, or DNS.

The DNS runs on servers all over the world, known as DNS resolvers.

You probably use the DNS resolver run by your internet service provider, if you got the router from them and never changed the settings.

The trouble with these default lookup systems is that, often, they are not very discerning: If your second grader types in Pornhub.com, that DNS resolver will go right ahead and resolve that to its IP address, and send your kid out into an area of the internet they shouldn’t yet know about.

If you look up a site that will deliver malware to your computer, the DNS resolver may just be like: Yes, go right ahead.