| title: | Layer |
|---|---|
| description: | What is a Deis Layer? |
| keywords: | layer |
:ref:`Layers <layer>` are homogeneous groups of :ref:`Nodes <node>` that perform work on behalf of a formation. Each node in a layer has the same :ref:`Flavor` and Chef configuration, allowing them to be scaled easily.
Runtime layers service requests and run background tasks for the formation. Nodes in a runtime layer use a Chef databag to deploy :ref:`Containers <container>` running a specific :ref:`Release`.
Proxy layers expose the formation to the outside world. Nodes in a proxy layer use a Chef databag to configure routing of inbound requests to :ref:`Containers <container>` hosted on runtime layers.
It is also possible to create custom layers that contain custom run-lists.