How to use browser caching mechanisms to reduce repeated resource loading?

When the browser caching mechanism is properly configured, there is no need to re-download stored resources during repeated visits to a website, thereby reducing redundant loading. This goal is typically achieved by setting HTTP cache headers, resource versioning, and negotiation-based validation. The main methods include: - Configuring the Cache-Control header: Set a long max-age (e.g., 31536000 seconds) for static resources (such as images, CSS/JS) to implement long-term caching; set no-cache or a short max-age for dynamic content (such as API responses) to ensure content timeliness. - Using ETag/Last-Modified: The server returns a resource identifier (ETag) or modification time (Last-Modified). When the browser requests again, it carries this information. If the resource has not changed, a 304 Not Modified response is returned to avoid full transmission. - Resource versioning: Add a hash to static resource filenames (e.g., style.v2.css). When updating resources, change the version number to ensure the browser loads new content instead of old caches. It is recommended to regularly check the cache status through browser developer tools and combine CDN to optimize resource distribution, further improving cache efficiency and loading speed.