Difference between IAC and ARM templates. ARM templates are used to provision/configure your resources, now you may use the same ARM template file and edit it slighty and use it for other environments such as Dev/QA. For utilizing different versions of the same ARM template we use IAC. So in short whenever ARM Templates are versioned and you need to choose which specific ARM template needs to be used, you will use IAC.
Difference between IAC and ARM templates. ARM templates are used to provision/configure your resources, now you may use the same ARM template file and edit it slighty and use it for other environments such as Dev/QA. For utilizing different versions of the same ARM template we use IAC. So in short whenever ARM Templates are versioned and you need to choose which specific ARM template needs to be used, you will use IAC.
Carried devops mid2 too
Hope this helps you in the final as well