# Tiered Cache
import DocButton from '~/components/webkit/DocButton.vue';
**Tiered Cache** is an **Cache** module that creates an additional cache layer between the edge and your origin servers, reducing latency and infrastructure costs.
When accessing your applications on Azion, your end-user accesses the edge network, where your content is cached. By enabling Tiered Cache in Applications, you can:
- Cache at a second layer at the edge.
- Keep your content cached for longer periods of time.
- Select the best region to keep cache closer to your users.
:::note
Tiered Cache is only available if the service has been activated for your account. To activate **Tiered Cache**, [contact the Sales team](https://www.azion.com/en/contact/).
:::
## Implementation
| Scope | Resource |
| --- | --- |
| Cache module | [Cache](/en/documentation/products/build/applications/cache/) |
| Creating a cache setting | [How to configure cache policies for Applications](/en/documentation/products/guides/cache-settings/) |
---
## Recommended TTL
**Tiered Cache** is specially designed for objects that can remain in cache for a long period of time. Thus, you can only activate it on cache policies with a TTL equal to or greater than *3 seconds*, with the default TTL being *60 seconds*.
---
## Regions
When you enable **Tiered Cache** as an extra caching layer, the edge servers of this second caching layer are hosted in the US (`na-united-states`) by default.
Azion also offers the option of hosting the Tiered Cache servers in Brazil (`sa-brazil`). To switch between regions in your applications, please contact the [Sales team](https://www.azion.com/en/contact/).
---
## Real-Time Purge
Whenever necessary, you can use **Real-Time Purge** to expire your **Tiered Cache** content before the expected TTL time. Remember to purge first from the tiered cache layer and only later from **Cache**. This avoids edge feedback with outdated Tiered Cache content.
---
## Limits
:::tip
**Increase limits**
You can request to increase the limits based on your plan. Contact the [technical support team](/en/documentation/services/support/) to request it.
:::
These are the **default limits**:
| Scope | Limit |
| --- | --- |
| Minimum TTL in Tiered Cache¹ | 3 seconds |
| Maximum TTL in Tiered Cache | 2,592,000 seconds |
> ¹ The **Tiered Cache** module currently doesn't support bypass cache. You can [configure a Bypass Cache rule](/en/documentation/products/build/applications/rules-engine/#bypass-cache) for caching at the edge, but applications with active Tiered Cache settings will continue to keep caching in that layer for the specified minimum TTL.