Which feature is NOT available in the free tier of Terraform Cloud?

The feature not available in the free tier of Terraform Cloud is audit logging. In Terraform Cloud, audit logging is a premium feature that allows organizations to track and log all user activities and changes within their infrastructure. This is particularly important for compliance and security purposes, as it provides visibility into who made what changes and when.

In contrast, the other mentioned features are part of the free tier. A private module registry allows users to store and share Terraform modules privately within their organization. Remote state management is essential for teams to securely store their Terraform state files in a centralized location, preventing conflicts and enabling collaboration. Workspaces provide a mechanism for organizing and managing different environments or versions of infrastructure, facilitating the management of multiple variants of a setup. These features are fundamental for collaborative deployments and are thus included in the free tier, while audit logging is reserved for higher tiers due to the additional resources and management it requires.