what is the difference between virtual machine classic and virtual machine in azure?

Question

In Azure there are 2 options available to create virtual machines. A. normal VM B. Classic VM

Does anybody know what is the difference between both option? When do we use one over other?

Answer 1

Short answer to your question is Normal VM or Virtual Machines is the new way of deploying your Virtual Machines whereas Classic VM or Virtual Machines (Classic) is the old way of deploying them. Azure is pushing towards the new way of deploying resources so the recommendation would be to use it instead of old way. However please keep in mind that there're some features which are available in the old way that have not been ported on to the new way so you just have to compare the features offered and only if something that you need is not available in new way, you use the old way.

Now comes the long answer :)

Essentially there's a REST API using which you interact with Azure Infrastructure.

When Azure started out, this API was called Service Management API (SMAPI) which served its purpose quite well at that time (and to some extent today). However as Azure grew, so does the requirements of users and that's where SMAPI was found limiting. A good example is access control. In SMAPI, there was access control but it was more like all-or-none kind of access control. It lacked the granularity asked by users.

Instead of patching SMAPI to meet user's requirement, Azure team decided to rewrite the entire API which was much simpler, more robust and feature rich. This API is called Azure Resource Manager API (ARM). ARM has many features that are not there in SMAPI (my personal favorite is Role-based access control - RBAC).

If you have noticed that there are two Azure portals today - https://manage.windowsazure.com (old) and https://portal.azure.com (new). Old portal supports SMAPI whereas new portal supports ARM. In order to surface resources created via old portal into new portal (so that you can have a unified experience), Azure team ended up creating a resource provider for old stuff and their names will always end with (Classic) so you will see Virtual Machines (Classic), Storage Accounts (Classic) etc. So the resources you create in old portal can be seen in the new portal (provided the new portal supports them) but any resources you create in the new portal using ARM are not shown in the old portal.