The Domain Name System protocol is a vital component of the internet. Without it there would be no World Wide Web. DNS matches the name of a website to its numerical IP address. DNS then communicates with root servers, which connects you to a website.
You may occasionally see an error message in your browser if there’s a problem with a website or you lose your internet connection.
Your browser may tell you to check your DNS settings. Thankfully this is usually unnecessary. In most situations, try refreshing the page or checking you’re still connected. If all else fails, make a cup of tea and try again.