Azure Loadbalancer

Spreads incoming requests to multiple servers to handle load so that incoming requests don't pile up and response time don't increase.

Azure uses simple random distribution of traffic.

Azure load balancer distributes loads to VMs inside of the same "load balanced set".

Availability sets - protect against downtime
Loadbalanced set - improves response time

In practice, they are same.

There are three types of load balancing in azure:

1. Traffic Manager - DNS Level, distributing to different data centers based on geo-location
2. Azure Load Balancer - Network level, distributes traffic from outside of Azure to VMs/Service inside of Azure
3. Internal Load Balancer - Network level, distributes traffic from inside of Azure to VMs/Service inside of Azure

http://bit.do/configure-load-balanced-set
http://bit.do/configure-internal-load-balanced-set