The cache needs to be updated because data changes. And this should be done with minimal costs. It strongly affects First Contentful Paint (FCP), because determines the time until the first byte is received from the server.
- Resistant to high loads
When there are a lot of requests to the site, then refreshing the page can lead to a strong load on the hosting. To prevent this, when the page is refreshed, parallel requests to the same page use the cached data. But the request initiating this update is waiting for the update to complete. And the next point helps to avoid this too.
- Lazy page refresh
Allows pages to always be fetched from the cache, even when data is being refreshed. It is very useful when search engines (especially Google and Bing) constantly monitor page speed due to an optimized page always returns quickly. Configurable here.
- Tracking changes on the site
When the page is changed, the cache is automatically refreshed. The dependent pages are also updated, such as the main page, list of records, archives. It is customizable at necessity.