Terraform is a tool to build an infrastructure safely and efficiently. Terraform can manage leading and popular service providers as well as custom in-house solutions.

The Configuration file in Terraform describes the components needed to run a single application or your entire Datacenter. Terraform then generates an execution plan describing what it will do to reach the desired state, and then executes it to build the described infrastructure. It creates incremental execution plans which can be applied according to the configuration change.

The infrastructure Terraform can manage includes low-level components such as compute instances, storage, and networking, as well as high-level components such as DNS entries, SaaS features, etc.

• Terraform is an open-source, Cloud-agnostic provisioning tool that supported Immutable Infrastructure, a Declarative language, a masterless and Agentless Architecture, and had a large community and a mature codebase.
• Infrastructure is described using a high-level configuration syntax. This allows a blueprint of your datacenter to be versioned and treated as you would any other code. Additionally, Infrastructure can be shared and re-used.
• Terraform builds a graph of all your resources, and parallelizes the creation and modification of any non-dependent resources. Because of this, Terraform builds infrastructure as efficiently as possible, and operators get insight into dependencies in their infrastructure.
• Terraform has a “Planning” step where it generates an execution plan. The execution plan shows what Terraform will do when you call apply. This lets you avoid any surprises when Terraform manipulates Infrastructure.
• Complex changesets can be applied to your infrastructure with minimal human interaction. With the previously mentioned execution plan and resource graph, you know exactly what Terraform will change and in what order, avoiding many possible human errors.