Google Cloud BOM (Maven artifact ID com.google.cloud:google-cloud-bom) lists Google Cloud Java client libraries. The Google Cloud Libraries BOM imports Google Cloud BOM.

Google Cloud recommends Java users to use the Libraries BOM (Maven artifact ID com.google.cloud:libraries-bom), instead of Google Cloud BOM. It's because the Libraries BOM sets the consistent versions of libraries including the core Java libraries. Cloud's documentation and samples also use the Libraries BOM.