Terraform is an open-source infrastructure as code (IaC) tool created by HashiCorp. It allows users to define and manage their cloud infrastructure using a high-level configuration language called HCL (HashiCorp Configuration Language). With Terraform, users can automate the provisioning and management of resources across various cloud providers, such as AWS, Azure, and Google Cloud. By using Terraform, teams can version control their infrastructure, making it easier to track changes and collaborate. The tool enables users to create, update, and delete resources in a safe and predictable manner, reducing the risk of human error and ensuring consistency across environments.