Merge pull request #31357 from anubha-v-ardhan/Add-event-to-glossary

Add "event" to glossary

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

@@ -0,0 +1,25 @@
+---
+title: Event
+id: event
+date: 2022-01-16
+full_link: /docs/reference/kubernetes-api/cluster-resources/event-v1/
+short_description: >
+   A report of an event somewhere in the cluster. It generally denotes some state change in the system.
+aka: 
+tags:
+- core-object
+- fundamental
+---
+Each Event is a report of an event somewhere in the {{< glossary_tooltip text="cluster" term_id="cluster" >}}. 
+It generally denotes some state change in the system.
+
+<!--more-->
+Events have a limited retention time and triggers and messages may evolve with time. 
+Event consumers should not rely on the timing of an event with a given reason reflecting a consistent underlying trigger, 
+or the continued existence of events with that reason. 
+
+
+Events should be treated as informative, best-effort, supplemental data.
+
+In Kubernetes, [auditing](/docs/tasks/debug-application-cluster/audit/) generates a different kind of
+Event record (API group `audit.k8s.io`).