Resources are the most important element in the Terraform language. Each resource block describes one or more infrastructure objects, such as virtual networks, compute instances, or higher-level components such as DNS records.
Syntax
A resource block declares a resource of a specific type with a local name (the name is used as a reference by terraform but not used outside the module)
resource "aws_instance" "web" {
// config here
}
In this case, the aws_instance resource is named web.
Config documentation
Each resource has their own documentation, usually found in the registry