Terraform Internals
This section covers the internals of Terraform and explains how plans are generated, the lifecycle of a provider, etc. The goal of this section is to remove any notion of "magic" from Terraform. We want you to be able to trust and understand what Terraform is doing to function.
Note: Knowledge of Terraform internals is not required to use Terraform. If you aren't interested in the internals of Terraform, you may safely skip this section.
© 2018 HashiCorpLicensed under the MPL 2.0 License.
https://www.terraform.io/docs/internals/index.html