What is DAX

  • DAX = Data Analysis Expressions
  • a language for defining measures and columns in Power BI data models.

What is DAX

Used in:

  • Power BI
  • SQL Server Analysis Services (SSAS)
  • Azure analysis services
  • Excel Power Pivot

Purpose of DAX

We use DAX to be able to create new information from the data that we already have. For example, if we have two columns, one column for the quantity sold and another for unit price, we can use DAX to create a formula that will calculate the total price for that item.


Power BI DAX Syntax Step 1

DAX vs M

Data Expression Language Data Preparation Language
PowerBI, SSAS Azure Analysis Services Default language of Power Query, Microsoft Flow

DAX vs Power Query

DAX is used for Measures/Calculations (i.e Agrregate meausre, Adding calculated column etc.)

Power Query (M) is used for data preparation (Cleaning, Transformation etc.)