The product
Looker Studio — formerly Google Data Studio — is a free, browser-based reporting tool. You connect data sources, define charts on a canvas, and share reports with a link, much like Google Docs.
It is strongest as a presentation and light-analysis layer over data that is already clean, particularly Google's own products: Google Analytics, Google Ads, Search Console, Sheets and BigQuery.
Looker Studio is not Looker
Looker (now Looker in Google Cloud) is a separate, paid enterprise platform built around LookML, a semantic modelling language. It governs metric definitions centrally across an organisation.
Looker Studio shares the brand and nothing else architecturally. It has no semantic modelling layer, no LookML, and no version control in the engineering sense. Conflating the two is a common interview mistake.
Looker Studio Pro adds team content management, Google Cloud project association and SLA support — it does not change the underlying engine.
Where it fits
Use it when: data is already modelled elsewhere, the audience is small to medium, cost matters, and the reporting needs are dashboards rather than deep ad-hoc exploration.
Do not use it as a transformation layer. It has calculated fields and blending, but no equivalent of Power Query or dbt. Shape the data upstream — in BigQuery, in Sheets, or in your warehouse — and let Looker Studio present it.
Performance is bounded by the connector. A report on a slow source will be slow, and there is limited tuning available beyond caching and extracts.