What is a workspace in Terraform?

A workspace in Terraform refers to a mechanism that allows users to manage multiple state files within a single configuration. This capability enables users to maintain different versions of infrastructure, facilitate different environments (like development and production), or create distinct configurations without the need to change the overall structure of the Terraform code itself.

When working with workspaces, each workspace has its own isolated state, which means that resources created in one workspace do not interfere with those in another. This is particularly useful for teams that want to manage several variations of an environment using the same configuration file, as it promotes organization and reduces the complexity that comes with managing separate configurations for each environment.

The other choices do not accurately describe what a workspace is. While modules are indeed for reusable code, they are not the same as workspaces. Workspaces do not define resources directly; rather, they manage state for those resources. Additionally, while workspaces can be used in different environments, the term itself does not specifically refer to an environment setup for testing. Instead, they can serve various purposes based on how you want to structure your infrastructure and manage your states.