Summary  
This chapter introduces the concept of building a sequence of repeatable, step‐by‐step data transformations—such as renaming columns, changing data types, and filtering rows—in a query editor that preserves the original source and automatically reapplies all steps on data refresh.  

General domain of usage  
Data cleaning and transformation in ETL workflows for analytics.

Before you can build reliable reports, you need reliable data. Power Query is Power BI's built-in tool for cleaning and transforming raw data before it enters your data model. In this chapter, you'll learn what Power Query is, how it fits into the Extract-Transform-Load (ETL) workflow, and why cleaning data before analysis is essential.

You'll take a guided tour of the Power Query Editor, including the Queries pane, data preview area, and the Applied Steps pane. You'll also learn that Power Query never modifies your original files, so you can experiment freely without risk.



What does the Applied Steps pane in Power Query show you?

Master the skills needed to turn raw data into professional, interactive reports using Power BI. You'll connect to data sources, clean and transform data with Power Query, build data models, write DAX measures, and publish polished dashboards to Power BI Service. No prior experience required.

What Is Power Query?