DNS is your computers address book.

If you want to go to ‘Daves house’ you need to translate that into an address first, which you can then travel to.

Your computer does the same thing, first translating ‘youtube.com’ into an IP address to connect to.

If your DNS/address book is broken or inaccessible, you can still connect to the internet/travel, but you really struggle to figure out where to actually go.

DNS or Domain Name Service is like the contacts list of the internet, so the service that turns the ‘your mom’ part of ‘call your mom about our date tonight’ into your mom’s phone number. It’s also the most common break point of a network connection in #currentyear because it’s difficult to automate testing for it on the other end of the connection (i.e. I can see that your mom’s phone number is listed on the dns billboard but that doesn’t mean you can see it from your house).

Fixing it is usually trivial, by either changing which DNS server you’re using (instead of the list of names provided by the ISP, you instead ask the panopticon google or cloudflare directly), or having your own server which you presumably know how to fix if it breaks.

DNS is a system used to convert a domain name (for example google.com) into an IP address. When something goes wrong with your DNS resolver (that’s the server your device contacts to convert domains into IPs), it’ll appear as if your internet connection isn’t working, and DNS is often the cause of such an error.