BLANK VS NULL VS EMPTY

sergiotb2001  perhaps this could give you more clarity: https://community.fabric.microsoft.com/t5/Service/Difference-between-blank-and-empty-in-advanced-filtering/m-p/1690495#:~:text=in%20the%20service.-,BLANK%20is%20the%20equivalent%20of%20null%2C%20while%20%22empty%22%20is,%22%20(an%20empty%20string).&text=Would%20you%20agree%3F&text=So%20even%20though%20the%20value,column%20has%20no%20selectable%20values.

https://community.fabric.microsoft.com/t5/Desktop/How-to-deal-with-null-value-and-blank-value-in-power-Query/td-p/2462982

Otherwise, you have it the other way, if you have text, it is empty "", if it is number, it is "null".

If it is number, it can be only "blank" 

If it is text, it can be blank (null) or empty "".

A colleague of mine once explained to me, that sometimes this is used to distinguish whether the user on purpose filled the filed empty "" or did not fill the value at all. Perhaps somebody could elaborate on this further...