DNS Prefetch
DNS Prefetch is a web performance optimization technique that resolves domain names to IP addresses in advance, before a user clicks on a link or loads a resource. It reduces latency by performing DNS lookups for external domains during browser idle time, speeding up subsequent page loads. This is implemented through HTML link tags with the 'rel="dns-prefetch"' attribute or HTTP headers.
Developers should use DNS Prefetch when building websites with multiple external resources (e.g., third-party APIs, CDNs, or social media widgets) to improve user experience by reducing load times. It's particularly useful for high-traffic sites where even small latency reductions matter, such as e-commerce platforms or content-heavy pages, as it minimizes delays caused by DNS resolution.