initial add, need to create diagram to replace placeholder

Signed-off-by: Hannah Hunter <hannahhunter@microsoft.com>

daprdocs/content/en/operations/resiliency/health-checks/sidecar-health.md

@@ -13,6 +13,10 @@ Dapr provides a way to determine its health using an [HTTP `/healthz` endpoint](
 
 In this guide, you learn how the Dapr `/healthz` endpoint integrate with health probes from the application hosting platform (for example, Kubernetes). 
 
+The following diagram demonstrates how Dapr checks for outbound health connections from the sidecar using `v1.0/healthz/outbound`, as shown by the green boundary lines. With this behavior, Dapr waits for a successful response from `v1.0/healthz/outbound`, rather than waiting for the Dapr HTTP port to be available. This provides a more explict implementation that is better isolated from accidental change.
+
+<img src="/images/security-mTLS-dapr-system-services.png" width="800" alt="Diagram of Dapr services interacting" />
+
 When deploying Dapr to a hosting platform like Kubernetes, the Dapr health endpoint is automatically configured for you.
 
 {{% alert title="Note" color="primary" %}}

daprdocs/content/en/reference/api/health_api.md

@@ -6,34 +6,75 @@ description: "Detailed documentation on the health API"
 weight: 1000
 ---
 
-Dapr provides health checking probes that can be used as readiness or liveness of Dapr.
+Dapr provides health checking probes that can be used as readiness or liveness of Dapr. 
 
 ## Get Dapr health state
 
-Gets the health state for Dapr.
+Gets the health state for Dapr by either:
+- Waiting for a specific health check against `v1.0/healthz/outbound`; or
+- Waiting for the Dapr HTTP port to become available
 
-### HTTP Request
+### Wait for Dapr HTTP port to become available
+
+With this behavior, Dapr waits for the Dapr HTTP port to become available to 
+
+#### HTTP Request
 
 ```
 GET http://localhost:<daprPort>/v1.0/healthz
 ```
 
-### HTTP Response Codes
+#### HTTP Response Codes
 
 Code | Description
 ---- | -----------
-204  | dapr is healthy
-500  | dapr is not healthy
+204  | Dapr is healthy
+500  | Dapr is not healthy
 
-### URL Parameters
+#### URL Parameters
 
 Parameter | Description
 --------- | -----------
-daprPort | The Dapr port.
+daprPort | The Dapr port
 
-### Examples
+#### Examples
 
 ```shell
 curl -i http://localhost:3500/v1.0/healthz
 ```
 
+### Wait for specific health check against `/outbound` path
+
+With this behavior, Dapr waits for a successful response from `v1.0/healthz/outbound`, rather than waiting for the Dapr HTTP port to be available. This provides a more explict implementation that is better isolated from accidental change.
+
+For example, [in the .NET SDK,](https://github.com/dapr/dotnet-sdk/blob/17f849b17505b9a61be1e7bd3e69586718b9fdd3/src/Dapr.Client/DaprClientGrpc.cs#L1758-L1785) if the ordering of a Dapr runtime init ever changed (accidentally or deliberately), and the Dapr HTTP port was open _before_ all components were initialized, this would cause a break in behavior.
+
+#### HTTP Request
+
+```
+GET http://localhost:<daprPort>/v1.0/healthz/outbound
+```
+
+#### HTTP Response Codes
+
+Code | Description
+---- | -----------
+204  | Dapr is healthy
+500  | Dapr is not healthy
+
+#### URL Parameters
+
+Parameter | Description
+--------- | -----------
+daprPort | The Dapr port
+ 
+#### Examples
+
+```shell
+curl -i http://localhost:3500/v1.0/healthz/outbound
+```
+
+## Related articles
+
+- [Sidecar health]({{< ref "sidecar-health.md" >}})
+- [App health]({{< ref "app-health.md" >}})