Azure Monitor for VMs includes a set of performance charts that target several key performance indicators (KPIs) to help you determine how well a virtual machine is performing. The charts show resource utilization over a period of time so you can identify bottlenecks, anomalies, or switch to a perspective listing each machine to view resource utilization based on the metric selected.
By using Azure Monitor for VMs health, you can actively monitor the availability and performance of a Windows or Linux guest OS.
Viewing the overall health state of an Azure VM and the underlying OS can be observed from two perspectives: directly from a VM, or across all VMs in a resource group from Azure Monitor.
Please refer to these documents on How to monitor VM's performance using Azure Monitor
and Understand the health of your Azure virtual machines