I would like to know the difference between the two. I dont find a specific explanation and also there is no specific documentation pertaining to Placement groups. It is always explained in relation to an Availaibilty set similar to the link belo. It is ecplained that it is similar to placement groups, but when to use one over the other?

<https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-placement-groups>

The only closest difference I was able to find was that the Azure Placement group maintains its own fault and update domains. But isnt that what Availability sets also focus on, separate fault and update domains?