Terraform is HashiCorp's open-source Infrastructure-as-Code tool that enables teams to define, provision, and manage cloud infrastructure using declarative configuration files written in HCL (HashiCorp Configuration Language). It describes the desired end-state of infrastructure rather than step-by-step instructions, and automatically determines the actions needed to reach that state. Terraform maintains a state file that tracks the real-world resources it manages, allowing it to calculate precise changes needed when configurations are updated.
The platform supports over 1,000 providers for managing resources across AWS, Azure, Google Cloud, Kubernetes, GitHub, Cloudflare, and hundreds of other services. Terraform's modular architecture allows teams to compose reusable infrastructure modules that encode organizational best practices and can be shared via the Terraform Registry. Key features include execution plans that preview changes before applying them, resource dependency graphing for optimal provisioning order, and state locking to prevent concurrent modification conflicts.
Terraform serves DevOps engineers, platform teams, and infrastructure architects who need to manage multi-cloud environments consistently and reproducibly. HCP Terraform (formerly Terraform Cloud) adds collaboration features including remote state storage, team access controls, policy enforcement via Sentinel, and cost estimation for planned changes. The tool is widely adopted across enterprises for provisioning everything from virtual machines and databases to DNS records and monitoring dashboards, making it the most popular IaC solution in the industry.