Exam DP203 Course Tybul 08 Data lake structure Raw layer
https://www.youtube.com/watch?v=02hf1UxRBIk
Raw layer. 1-1 data
Immutable - which means "unchanging". Retained forever.
Business or regulatory requirement might mean you have to anonymise data when it is imported into the staging layer.
In all other cases, load the data in the same format as it is read from the source, with as few changes as possible.