Redshift cluster elastic or classic resize on `node_type` and `number_of_nodes` change?

AWS offers two ways to resize a Redshift cluster. Classic or Elastic resize. How can I determine and confirm which one of these resize actions that will be taken as a result of updating the node_type and number_of_nodes attributes of the aws_redshift_cluster resource? The Terraform plan only shows that a change will be done in place, but not “how”.