# Cache and deliver pages

How pages are cached and delivered on Cloud Platform, and what to do when readers see stale content. Start with [how caching works](/cloud-platform/caching/guide/).

- [How caching works](/cloud-platform/caching/guide/): What sits between a visitor and your Drupal code (Varnish in front, memcached behind), what makes a response cacheable, and how Drupal's cache settings feed the platform layer.
- [Fix stale content](/cloud-platform/caching/stale-content/): Your deploy went out but production still shows the old page. Read the response headers to find which cache layer is serving it, then purge the right one.