I was wondering if ARM Templates can replace Terraform. Or is it more like AWS Cloudformation?
No it is not, and it won’t be 🙂
The most obvious difference to distinguish between Terraform and ARM Templates is that: Terraform is stateful and ARM Templates is stateless. You use Terraform if you want to keep to keep a strong consistency of your cloud infrastructure with what you define. You use ARM Templates if you just want a systematically deployment of your infrastructure and then you can modify it at will.