What is the purpose of the 'terraform plan' command?

The 'terraform plan' command plays a crucial role in the Terraform workflow by allowing users to preview the changes that will be made to the infrastructure before they are actually applied. This command generates an execution plan, which outlines the actions Terraform will take to reach the desired state as defined in your configuration files. By using 'terraform plan', you can see what resources will be created, modified, or destroyed, providing an opportunity to review those changes before executing them with 'terraform apply'. This helps prevent unexpected alterations to the infrastructure and aids in ensuring that the changes align with your intentions.

The other options serve different functions within Terraform but do not describe the specific purpose of the 'terraform plan' command. Destruction of infrastructure is managed through a different command, validation of configurations is typically performed with 'terraform validate', and initializing the directory is done using 'terraform init'. Thus, the primary and vital usage of 'terraform plan' is to preview infrastructure changes, making it essential for safe and effective infrastructure management.