Update for the BATCH metrics API release

Author: rboucher

articles/azure-monitor/essentials/data-platform-metrics.md

@@ -54,10 +54,17 @@ Azure Monitor collects metrics from the following sources. After these metrics a
 - **Applications**: Application Insights creates metrics for your monitored applications to help you detect performance issues and track trends in how your application is being used. Values include _Server response time_ and _Browser exceptions_.
 - **Virtual machine agents**: Metrics are collected from the guest operating system of a virtual machine. You can enable guest OS metrics for Windows virtual machines by using the [Windows diagnostic extension](../agents/diagnostics-extension-overview.md) and for Linux virtual machines by using the [InfluxData Telegraf agent](https://www.influxdata.com/time-series-platform/telegraf/).
 - **Custom metrics**: You can define metrics in addition to the standard metrics that are automatically available. You can [define custom metrics in your application](../app/api-custom-events-metrics.md) that's monitored by Application Insights. You can also create custom metrics for an Azure service by using the [custom metrics API](./metrics-store-custom-rest-api.md).
-- **Kubernetes clusters**: Kubernetes clusters typically send metric data to a local Prometheus server that you must maintain. [Azure Monitor managed service for Prometheus ](prometheus-metrics-overview.md) provides a managed service that collects metrics from Kubernetes clusters and store them in Azure Monitor Metrics. The Metrics Dataplane API is a high-volume API designed for customers with large volume metrics queries. Similar to the existing ARM metrics API, it provides the capability to retrieve metric data for up to 50 resource IDs in the same subscription and region in a single batch API call, improving query throughput and reducing the risk of throttling. The current metrics API is the most queried API in ARM API, but customers who leverage it for bulk queries at high frequency and push metrics to other datastores for deep analytics may experience throttling issues. The Metrics Dataplane API provides higher query limits to address these issues and enable customers to query metrics without the risk of throttling. Customers can learn more about this API by visiting the link provided.
+- **Kubernetes clusters**: Kubernetes clusters typically send metric data to a local Prometheus server that you must maintain. [Azure Monitor managed service for Prometheus ](prometheus-metrics-overview.md) provides a managed service that collects metrics from Kubernetes clusters and store them in Azure Monitor Metrics.
 
 For a complete list of data sources that can send data to Azure Monitor Metrics, see [What is monitored by Azure Monitor?](../monitor-reference.md).
 
+## REST API 
+Azure Monitor provides REST APIs that allow you to get data in and out of Azure Monitor Metrics.
+- **Custom metrics API** - [Custom metrics](./metrics-custom-overview.md) allow you to load your own metrics into the Azure Monitor Metrics database. Those metrics can then be used by the same analysis tools that process Azure Monitor platform metrics. 
+- **Azure Monitor Metrics REST API** - Allows you to access Azure Monitor platform metrics definitions and values. For more information, see [Azure Monitor REST API](/rest/api/monitor/).  For information on how to use the API, see the [Azure monitoring REST API walkthrough](./rest-api-walkthrough.md).
+- **Azure Monitor Metrics Data plane REST API**  - [Azure Monitor Metrics data plane API](/rest/api/monitor/metrics-data-plane/) is a high-volume API designed for customers with large volume metrics queries. It's similar to the existing standard Azure Monitor Metrics REST API, but provides the capability to retrieve metric data for up to 50 resource IDs in the same subscription and region in a single batch API call. This improves query throughput and reduces the risk of throttling.   
+
+
 ## Metrics Explorer
 
 Use [Metrics Explorer](metrics-charts.md) to interactively analyze the data in your metric database and chart the values of multiple metrics over time. You can pin the charts to a dashboard to view them with other visualizations. You can also retrieve metrics by using the [Azure monitoring REST API](./rest-api-walkthrough.md).