Configure and Manage Public cloud with Azure is piece of cake same way configuring high availability for virtual machine is very simple with feature availability zone and availability set. With the availability zone we can manually select the Datacenter option from 1 to 3 in the same building or region. availability set provide a group of two or more vm to ensure that at least one is available during planned or unplanned events. availability option must need to configure while create a virtual machine as it can’t be changed after creation. Availability option expressly tell virtual machine that is identical or related such as webserver behind load balancer

Availability Zone :-

As we can see from below , we have option to select VM placement from Datacenter from 1 to 3  in same building or region.

Availability Set :-

with availability set azure is going to make an attempt to physically separate those machine so that something that would take down one VM won’t take down others and those might be bad power supply or a windows update or some kind of a patch so any unintended or intended downtime is minimized and it only works for two or more virtual machine.

Fault domain

FD is mainly related to physical problem such as power supply, network issues or switch issue, so if you deploy two VM across two FD then a single power supply or single network switch is not going to bring down VM. Fault domain maximum can be increased to 3 and default is 2.

Update Domains :-
there are 20 maximum update domains , so if we have 20 vms we cloud deploy 20 update domains and MS is going to roll out the patches from 1st to all the way up to 20 so vm can rebooted one at a time , default is 5

Visit also :-

https://docs.microsoft.com/en-us/azure/virtual-machines/windows/manage-availability