Hi@akhtar,
A module is a container for multiple resources that are used together. Every Terraform configuration has at least one module, known as its root module, which consists of the resources defined in the .tf files in the main working directory. To call a module means to include the contents of that module into the configuration with specific values for its input variables. Modules are called from within other modules using module blocks.
module "servers" {
source = "./app-cluster"
}