Note that Azure provides three main options to enhance availability for IaaS deployments, availability sets, Azure Site Recovery, and Availability Zone. You will need to know what each one of these does.
Describe Azure high availability and disaster recovery features for Azure Virtual Machines
You also want to study on what level of protection does each provide.
If I have a data center failure, which of these solutions will not give me the protection that I need?
Which one of these solutions will provide me protection against a regional failure?
These are the type of things that you’ll need to know for the exam related to this, and keep those features in mind.
Explore high availability and disaster recovery solution for IaaS
Describe high availability and disaster recovery for PaaS deployments
https://learn.microsoft.com/en-us/azure/reliability/overview-reliability-guidance