Terraform is an infrastructure as code tool that lets you build, change, and version cloud and on-prem resources safely and efficiently. It deploys infrastructure using providers, there are different providers available from HashiCorp (the owner of Terraform) and from the community. For that reason it is a widely known and used language to deploy infrastructure.

The core Terraform workflow consists of three stages:

• Write: You define resources, which may be across multiple cloud providers and services. For example, you might create a configuration to deploy an application on virtual machines in a Virtual Private Cloud (VPC) network with security groups and a load balancer.
• Plan: Terraform creates an execution plan describing the infrastructure it will create, update, or destroy based on the existing infrastructure and your configuration.
• Apply: On approval, Terraform performs the proposed operations in the correct order, respecting any resource dependencies. For example, if you update the properties of a VPC and change the number of virtual machines in that VPC, Terraform will recreate the VPC before scaling the virtual machines.

Useful links

• Hashicorp Terraform introduction page