Very Very Basic question about namespaces in C#

Hello,
This is a very basic question.
I always thought of the namespaces as logical grouping of classes.
In my company project when I tried to add a namespace. It gave me an error message
Error: Namespave does not correspond to a file location, should be Abc.Services.Tracking
Services and Tracking are folders inside the ABC project and I was trying to create a new class inside Tracking folder with a new namespace and it gave me the above error.
So does that mean the namespaces are physical collection of classes rather then logical.
If someone can kindly explain. Thanks.



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