system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Pornhub and YouPorn have both pledged to use encryption to block ISP's from using your traffic on those sites. How is this effective?

For instance, if I go to pornhub.com/kinky_video, how does Pornhub encrypting that video prevent my ISP from knowing that I went there? Couldn't they just look up pornhub.com/kinky_video and know what I watched?
gpt
When you go to a website, your computer first asks your DNS server (likely ran by your ISP) to translate the domain name into an IP address, eg pornhub.com to 31.192.120.36. Your computer then connects to the server at that IP address, and asks that computer "Send me pornhub.com/kinkyvideo".

You never asked your ISP for the URL. You asked your DNS server (again, likely ran by your ISP unless you changed it) to translate the domain name to an IP address, then all of the rest of the communication was between you and the pornhub server, your ISP isn't involved past being the carrier of the data.

Now, if your connection is not encrypted, anyone between you an the remote server (such as your ISP) can see the contents of your communications. They can see "oh hey, clevertoucan just requested pornhub.com/kinkyvideo'. However, if the connection is encrypted, all that your ISP knows is "clevertoucan just looked up the address for pornhub.com, then there was a stream of encrypted communication between the them." They have no knowledge of what is within that communication, including no knowledge of the specific URLs you visited.