Terraform and Terraform providers must use the same major version number in a single configuration.

This is false because Terraform's plugin architecture explicitly separates provider versioning from core CLI versioning, allowing each to follow its own release cadence independently.

Terraform providers are distributed as separate plugins with their own independent release and versioning lifecycle, completely decoupled from the Terraform CLI version. A provider such as the AzureRM provider can be at version 3.x while Terraform CLI is at version 1.x, and both interoperate correctly as long as the provider supports the plugin protocol version used by the CLI. Provider version constraints in the 'required_providers' block manage compatibility independently from the 'required_version' constraint for the CLI.