The fastest resource download is the one never made. Caching is a great way to ensure your content is positioned as close to your users as possible and that your repeat visitors get instant access to your content. Developers can impact the behavior of network and browser caches, improving content caching and ensuring it’s always as available as it can be, but caching semantics in HTTP can be confusing, which means that most content on the web today is not properly cached.
Yoav Weiss explores HTTP cache semantics, strategies, browser internal caches, and service workers and explains how serve your content fast and fresh.