In Terraform, what does the 'output' block do?

The 'output' block in Terraform is designed to define outputs that can be accessed after the execution of a Terraform configuration. This is particularly useful for debugging and providing important information about created resources. Outputs can display values that are computed by the configuration, such as resource identifiers or IP addresses, which can be important for users to reference later.

When a user runs terraform apply, the output values defined in the output block are presented to the user, making it easier to use the results of the Terraform run. This functionality helps in gaining insights into the provisioned infrastructure directly from the console and can also be utilized in subsequent Terraform configurations by referencing these outputs as variables.

While the other options may touch on aspects of Terraform's functionality, they do not accurately capture the specific purpose of the output block. Outputs are strictly meant for exposing computed values, rather than specifying resource states, declaring variables, or logging activities.