diff --git a/docs/concepts/workloads/controllers/deployment.md b/docs/concepts/workloads/controllers/deployment.md
index 1b6d3afa73..c9d327d586 100644
--- a/docs/concepts/workloads/controllers/deployment.md
+++ b/docs/concepts/workloads/controllers/deployment.md
@@ -43,6 +43,10 @@ In this example:
 
 * A Deployment named `nginx-deployment` is created, indicated by the `metadata: name` field.
 * The Deployment creates three replicated Pods, indicated by the `replicas` field.
+* The `selector` field defines how the Deployment finds which Pods to manage.
+  In this case, we simply select on one label defined in the Pod template (`app: nginx`).
+  However, more sophisticated selection rules are possible,
+  as long as the Pod template itself satisfies the rule.
 * The Pod template's specification, or `template: spec` field, indicates that
   the Pods run one container, `nginx`, which runs the `nginx`
   [Docker Hub](https://hub.docker.com/) image at version 1.7.9.