Update affinity.md

content/en/docs/reference/glossary/affinity.md

@@ -1,19 +1,22 @@
 ---
-title: affinity
+title: Affinity
 id: affinity
 date: 2019-01-11
-full_link: /docs/tasks/configure-pod-container/assign-pods-nodes-using-node-affinity/
+full_link: /docs/concepts/scheduling-eviction/assign-pod-node/#affinity-and-anti-affinity
 short_description: >
-  Node affinity is a set of rules used by the scheduler to determine where a pod can be placed.
+     Rules used by the scheduler to determine where to place pods
 aka:
 tags:
-- core object
 - fundamental
 ---
-Node affinity is a set of rules used by the scheduler to determine where a pod can be placed.
+
+In Kubernetes, _affinity_ is a set of rules that give hints to the scheduler about where to place pods.
 
 <!--more-->
+There are two kinds of affinity:
+* [node affinity](/docs/concepts/scheduling-eviction/assign-pod-node/#node-affinity)
+* [pod-to-pod affinity](/docs/concepts/scheduling-eviction/assign-pod-node/#inter-pod-affinity-and-anti-affinity)
 
-The rules are defined using the familiar concepts of custom labels on {{< glossary_tooltip term_id="node" text="nodes">}} 
+The rules are defined using the Kubernetes {{< glossary_tooltip term_id="label" text="labels">}},
 and {{< glossary_tooltip term_id="selector" text="selectors">}} specified in {{< glossary_tooltip term_id="pod" text="pods" >}}, 
 and they can be either required or preferred, depending on how strictly you want the scheduler to enforce them.