What's the difference between DAX and Power Query (or M)?

Question

I have been working on Power BI for a while now and I often get confused when I browse through help topics of it. They often refer to the functions and formulas being used as DAX functions or Power Query, but I am unable to tell the difference between these two. Please guide me.

Answer 1

• M and DAX are expression languages in Power BI. Both of them are similar to MS Excel expressions, as both of them are different from each other and are used differently for building Power BI models. 
• M can be viewed in Power Query Editor which is a query language. When transformations are done, expressions are automatically generated in M.To see the M expressions, enable formula bar on the view button.
• Data Analysis Expressions(DAX) is a language used for creating transformations in Power BI Desktop main screen. It uses various functions to work on data that is stored in tables
• To refer to functions in DAX, refer to this https://docs.microsoft.com/en-us/dax/dax-function-reference

• To refer to functions in Power Query M, refer to this

  https://docs.microsoft.com/en-us/powerquery-m/power-query-m-function-reference