DNS (Domain Name System) is a simple service that resolves a domain name (example.com) to its host (where the files are, e.g. 1.1.1.1). That's just it, nothing more.
By default you use a DNS service by your ISP (Internet Service Provider). But you can choose from many free DNS services from around the world or even self host a DNS server.
CDN (Content Delivery Network) is a service which caches files for the website. Videos, images, files, etc. It can also hide the actual address of the domain by proxying data.
The French court asked google to stop resolving domains for users using google DNS, so it cannot connect to it's host.
Google is arguing CDN services who know the actual address of these websites and redistribute files for these pirate sites should be better targets for the court than a DNS service.
I guess they're saying DNS blocks can easily bypassed by the users and the pirates can buy a new domain making it ineffective.
You know how tankies from ML turn up and defend any discussion critical of China and Russia?
Similarly, there are wankies who's default mode is to believe everything the western media says and use their propaganda taking points and deflect criticism.
Lemmyverse is a fun place where both get called out.
Most people won't go beyond the "sepernt = bad" logic ingrained in human brain.