---
title: Concepts
description: Core caching concepts including TTL, revalidation, and cache control.
image: https://developers.cloudflare.com/core-services-preview.png
---

> Documentation Index  
> Fetch the complete documentation index at: https://developers.cloudflare.com/cache/llms.txt  
> Use this file to discover all available pages before exploring further.

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# Concepts

Review the following topics to learn more about the basic concepts and components of Cloudflare Cache.

* [ CDN-Cache-Control ](https://developers.cloudflare.com/cache/concepts/cdn-cache-control/)
* [ Cloudflare cache responses ](https://developers.cloudflare.com/cache/concepts/cache-responses/)
* [ Customize cache ](https://developers.cloudflare.com/cache/concepts/customize-cache/)
* [ Default cache behavior ](https://developers.cloudflare.com/cache/concepts/default-cache-behavior/)
* [ Head Requests and Set-Cookie Headers ](https://developers.cloudflare.com/cache/concepts/cache-behavior/)
* [ Origin Cache Control ](https://developers.cloudflare.com/cache/concepts/cache-control/)
* [ Retention vs Freshness (TTL) ](https://developers.cloudflare.com/cache/concepts/retention-vs-freshness/)
* [ Revalidation ](https://developers.cloudflare.com/cache/concepts/revalidation/)

```json
{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/cache/","name":"Cache / CDN"}},{"@type":"ListItem","position":3,"item":{"@id":"/cache/concepts/","name":"Concepts"}}]}
```