DNS (Domain Name Service) plays a critical role in the operation of all web browsers. When you type in a domain, such as Tweaks.com, your browser must resolve the address into an IP address so your computer can talk to the site's server and download the web page. Once the page is downloaded, it is processed by the browser, which then can trigger hundreds of downloads as the various resources on the page are fetched. Many of these requests for resources go to different domains which also must be resolved before the browser can download the file. The result is a lot of domain resolutions, which makes the performance of your DNS provider critical to your web browsing speed.