Google Cloud Data Catalog is GCP's managed metadata and data discovery service. It indexes data assets - especially BigQuery datasets, tables, and views, plus Pub/Sub and Cloud Storage - and makes them searchable with tags and a business glossary. It is fully managed and serverless, and Google has folded it into Dataplex as the discovery layer of a broader governance platform.

Discovery and tagging

Data Catalog automatically catalogs BigQuery and Pub/Sub assets and lets you enrich them with tags based on tag templates - structured metadata (e.g., data owner, sensitivity, retention) attached consistently across assets. Users search the catalog with the same technology that powers Google's own search, finding tables by name, column, or tag. Tags can drive governance, including integration with column-level security and data masking in BigQuery.

What it provides

• Automatic cataloging of BigQuery, Pub/Sub, and Cloud Storage assets.
• Tag templates for structured, consistent business and governance metadata.
• Powerful search across the data estate.
• Integration with BigQuery security (column-level access, policy tags) and IAM.

Now part of Dataplex

Google has unified Data Catalog into Dataplex, which adds lineage, data quality, profiling, and lake/data-fabric governance around the catalog. New work on GCP governance centers on Dataplex, with Data Catalog as its discovery capability. If you're starting today, you'll generally engage with it through Dataplex.

Where it fits

• GCP/BigQuery-centric organizations needing discovery and consistent tagging.
• Driving BigQuery governance (policy tags, column security) from catalog metadata.

It is the Google counterpart to AWS Glue Catalog + Lake Formation and Azure Purview; the choice follows your cloud, and on GCP the path now runs through Dataplex.