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 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.