Google Cloud's serverless, highly scalable data warehouse. It lets you analyze petabytes of data with SQL without managing infrastructure. Pricing model based on data scanned or reserved slots.
In CDL it's the main analytics service. Difference from Cloud SQL (transactional database): BigQuery is for analyzing large volumes of data, not for OLTP operations. Question: analyze terabytes of historical logs → BigQuery.
BigQuery is a concept that can show up on the exam. Check the full guide to see it in context.