How does D’s ‘import’ work?

[Cecil Ward]

On Wednesday, 31 May 2023 at 18:43:52 UTC, Cecil Ward wrote:
> Is there an explanation of how D’s ‘import’ works somewhere? 
> I’m trying to understand the comparison with the inclusion of 
> .h files, similarities if any and differences with the process.

I have another question if I may, what do we do about getting 
makefiles right given that we have imports ?