AdGuard DNS answers queries for known advertising and tracking hostnames with an empty response, so ads never load. 94.140.14.14 / 94.140.15.15 are the default (blocking) servers; 94.140.14.140 is non-filtering; 94.140.14.15 adds family protection. Encrypted variants use dns.adguard-dns.com.
It is the simplest way to get network-wide ad blocking on a phone, console or smart TV without installing software.