Merge pull request #246141 from t-vnamani/patch-1

Update event-overview.md

Author: AnnaMHuff

articles/governance/policy/concepts/event-overview.md

@@ -16,23 +16,52 @@ pushed through [Azure Event Grid](../../../event-grid/index.yml) to subscribers
 Critically, you only pay for what you use.
 
 Azure Policy events are sent to the Azure Event Grid, which provides reliable delivery services to
-your applications through rich retry policies and dead-letter delivery. To learn more, see
-[Event Grid message delivery and retry](../../../event-grid/delivery-and-retry.md).
-
-The common Azure Policy event scenario is tracking when the compliance state of a resource changes
-during policy evaluation. Event-based architecture is an efficient way to react to these changes
-instead of scanning the compliance state of resources on a fixed schedule.
+your applications through rich retry policies and dead-letter delivery. Event Grid takes 
+care of the proper routing, filtering, and multicasting of the events to destinations via Event Grid subscriptions.
+To learn more, see [Event Grid message delivery and retry](../../../event-grid/delivery-and-retry.md). 
 
 > [!NOTE]
 > Azure Policy state change events are sent to Event Grid after an
 > [evaluation trigger](../how-to/get-compliance-data.md#evaluation-triggers) finishes resource
 > evaluation.
 
+## Event Grid Benefits
+Event Grid has a few benefits for customers and services in the Azure ecosystem: 
+- Automation: To stay current with your policy environment, Event Grid offers an automated mechanism to generate
+  alerts and trigger tasks depending on compliance states.
+- Durable delivery:  In order for services and user applications to respond in real-time to policy compliance events,
+  Event Grid seeks to offer policy events with minimum latency. Event Grid retries transmission of an event if a subscriber's
+  endpoint fails to acknowledge receipt of it or if it doesn't, according to a predetermined retry schedule and retry policy.
+- Custom event producer: Event Grid  event producers and consumers don't need to be Azure or Microsoft services.
+  External applications can receive an alert, show the creation of a remediation task or collect messages on who responds to the
+  state change.	
 See
 [Route policy state change events to Event Grid with Azure CLI](../tutorials/route-state-change-events.md)
 for a full tutorial.
 
-:::image type="content" source="../../../event-grid/media/overview/functional-model.png" alt-text="Event Grid model of sources and handlers" lightbox="../../../event-grid/media/overview/functional-model-big.png":::
+There are two primary entities when using Event Grid: 
+- Events: These events can be anything a user may want to react to that includes if a policy compliance state is
+   created, changed, and deleted of a resource such as a VM or storage accounts.
+- Event Grid Subscriptions: These event subscriptions are user configured entities that direct the proper set of events
+  from a publisher to a subscriber. Event subscriptions can filter events based on the resource path the event
+  originated from and the type of event. Additionally, Event Subscriptions can also filter by scope between
+  Azure subscription and Management group.
+
+A common Azure Policy event scenario is tracking when the compliance state of a resource changes
+during policy evaluation. Event-based architecture is an efficient way to react to these changes
+and aids in the event based reaction to compliance state changes.
+
+Another scenario is to automatically trigger remediation tasks without manually ticking off _create 
+remediation task_ on the policy page. Event Grid checks for compliance state and resources that are currently 
+noncompliant can be remedied. Learn more about [remediation structure](../concepts/remediation-structure.md).
+Remediation requires a managed identity and policies must be in Modify or DeployIfNotExists effect. [Learn more about
+effect types](../how-to/remediate-resources.md).
+
+Additionally, Event Grid is helpful as an audit system to store state changes and understand cause of noncompliance over 
+time. The scenarios for Event Grid are endless and based on the motivation, Event Grid is configurable. 
+
+
+:::image type="content" source="../../../event-grid/media/overview/functional-model.png" alt-text="Screenshot of Event Grid model of sources and handlers." lightbox="../../../event-grid/media/overview/functional-model-big.png":::
 
 [!INCLUDE [policy-events.md](../../../../includes/policy/policy-events.md)]