The Domain Name System (DNS) is one of the foundations of the internet, yet most people outside of networking probably don’t realize they use it every day to do their jobs, check their email or waste time on their smartphones.
At its most basic, DNS is a directory of names that match with numbers. The numbers, in this case are IP addresses, which computers use to communicate with each other. Most descriptions of DNS use the analogy of a phone book, which is fine for people over the age of 30 who know what a phone book is.
If you’re under 30, think of DNS like your smartphone’s contact list, which matches people’s names with their phone numbers and email addresses. Then multiply that contact list by everyone else on the planet.