M is the formula language behind Power Query. Every transformation you apply to your data is translated into M code. 

Knowledge of this language opens doors that remain closed when you only use the graphical interface.

In this session you will learn what else is possible by using the Advanced Editor, such as:
- Working with variables and data types
- Custom Columns and Time Intelligence Filtering
- Data grouping and sorting
- Creating table and scalar functions
- Crossjoin between 2 tables (make all possible combinations)

Recently, the Advanced Editor also has Intellisense, so now is the time to delve into M!

I gave this presentation at SQL Bits 2020.
Slides:
https://arthurgraus-my.sharepoint.com/:p:/g/personal/agmgraus_arthurgraus_nl/ERkp1u5dh-tKgXa6cq6MjfIBYyiQE6B-0SzmsFX4KFlfCg?e=mmvf5Z
Video:
https://ilovepowerbi.tips/2020/08/31/introduction-to-power-query-language-m/