Summary  
This chapter covers defining and applying a sequence of repeatable data transformation steps within an ETL pipeline, enabling non-destructive cleaning and reshaping of raw data before it enters a data model.  

General domain of usage  
Data preparation for business intelligence and 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.

Get hands-on experience with Power BI Desktop: understand where it fits in the modern data stack, install it, explore the interface, connect to your first dataset, and build your first bar chart.

Master the skills needed to clean, transform, and combine data using Power Query – from filtering rows and adding columns to merging tables and reshaping data with pivot operations.

Explore the essentials of relational data modeling and DAX – build star schemas, define relationships, write measures, and use time intelligence functions to answer real business questions.

Dive into the fundamentals of Power BI visuals – choose the right chart type, configure slicers and filters, add drillthrough navigation, and create bookmark-driven interactive experiences.

Transform the way you present data by applying layout and design principles, building multi-page reports, setting up row-level security, and publishing to Power BI Service with scheduled refresh.

Gain a solid understanding of the end-to-end Power BI workflow by completing a guided project – from data preparation and modeling to building a multi-page dashboard and publishing it to the Service.

What Is Power Query?