Before you can visit a site, you need to have the IP address. Your computer connects to DNS servers to get the IP address. Your ISP provides DNS servers, but you can point to other services that offer a more secure and potentially faster experience. Plus, all you need to do is change some numbers on your computer or router.
AT&T was caught selling users DNS records to advertisers , so just another reason to avoid your ISP's DNS service. Cloudflare is a leader in the realm of DNS privacy/security and offer an awesome DNS service called 220.127.116.11
The good folks are Lifewire.com have tons of great articles on the how and why for using DNS services.
- Set Up Cloudlare 18.104.22.168
- How to Change DNS Server Settings on Home Computer Networks
- List of Free and Public DNS Servers
- DNS Performance Video Report
DNS can leak information that would reveal your search query.