Drupal's advanced caching system utilizes cache-tags, cache-contexts, nested-cache-bubbling, and a flexible API to optimize website speed and efficiency. Cache-tags enable targeted cache updates for updated content, reducing load times. Cache-contexts personalize cached content based on user attributes, while nested-cache-bubbling refines cache clearing for quicker delivery of updated content. The flexible API empowers developers to customize caching rules, enhancing performance while delivering tailored experiences.