dbt (data build tool) is an open-source analytics engineering framework that transforms raw data in warehouses using SQL-first workflows with software engineering best practices. It enables teams to build modular, tested, and documented data pipelines directly in platforms like Snowflake, BigQuery, Databricks, and Redshift, treating transformations as code with version control, CI/CD, and automated testing. The tool's power lies in combining SQL transformations with Jinja templating, enabling dynamic, reusable logic while maintaining complete lineage tracking from raw sources to final models and BI exposures. One key mental model: dbt doesn't move data—it builds SELECT statements that your warehouse executes, making it a transformation-only tool in the modern ELT (Extract-Load-Transform) paradigm.