Скачать или смотреть Fix Expires Headers Leverage Browser Caching in Wordpress Website

The leverage browser caching warning, as shown below in the screenshot, is referring to your browser cache. Whenever you visit a website, it downloads assets, such as HTML, CSS, JavaScript and images into your browser’s local cache. This way it doesn’t have to retrieve them on every page load. The warning itself is returned when your web server, or a third-party server, doesn’t have the correct HTTP cache headers implemented. Or the headers might exist, but the cache time is set too short.
You might also see this warning in the new “think with Google” website speed test, which is powered by Google PageSpeed Insights. This was designed to be more of a marketing tool by Google, but this has resulted in lot of clients now simply forwarding these errors to their webmasters. Leaving WordPress developers and designers looking for ways to quickly fix it to appease their clients.