Availability Zones are physically separate datacenters within an Azure region. Each Availability Zone is made up of one or more data centers equipped with independent power, cooling, and networking.
* proximity group
A proximity placement group is a logical grouping used to make sure that Azure compute resources are physically located close to each other.
Proximity placement groups are useful for workloads where low latency is a requirement.
Placing VMs in a single region reduces the physical distance between the instances. Placing them within a single availability zone will also bring them physically closer together. However, as the Azure footprint grows, a single availability zone may span multiple physical data centers, which may result in a network latency impacting your application.
To get VMs as close as possible, achieving the lowest possible latency, you should deploy them within a proximity placement group.
A proximity placement group is a logical grouping used to make sure that Azure compute resources are physically located close to each other.
Proximity placement groups are useful for workloads where low latency is a requirement.
Low latency between stand-alone VMs.
Low Latency between VMs in a single availability set or a virtual machine scale set.
Low latency between stand-alone VMs, VMs in multiple Availability Sets, or multiple scale sets.
You can have multiple compute resources in a single placement group to bring together a multi- tiered application.
Low latency between multiple application tiers using different hardware types. For example, running the backend using M-series in an availability set and the front end on a D-series instance, in a scale set, in a single proximity placement group.