you want to go to
www.warez.com
your computer sends a request to your DNS server, asks where
www.warez.com is.
DNS server says, oh, that's at 192.168.1.1
your computer goes to 192.168.1.1
government decides that site is illegal. now your DNS server will respond to your request by telling you the site is at 192.168.200.200
That IP is a government webserver, giving you a nice message saying the domain is illegal.
So, instead, you change your DNS servers to blockaid. Now when you request
www.warez.com, it tells you the IP is 192.168.1.1
I would guess blockaid is just an offshore DNS server. You obviously have to have a certain amount of trust in them, as they can start redirecting you to whatever they want.
fairly simplified
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