Where can Terraform not load a provider from?

Terraform can load provider plugins from a local plugins directory, such as `.terraform/providers`, where they are installed during `terraform init`.

Terraform utilizes a provider plugin cache to store downloaded plugins, allowing it to load them from the cache without re-downloading if available.

Terraform loads official providers by downloading their compiled binaries from the official HashiCorp distribution hosted on `releases.hashicorp.com` during the `terraform init` process.

Terraform providers must be compiled into binary executables (plugins) before they can be loaded and used by Terraform; Terraform cannot directly load or execute provider source code files.