How do I split an single file Angular module into client, server, and share files?

I have been able to guess, often correctly, what goes into which file. I have had good results already by just looking at the content of the module as 3 files in a dotnet dotnet-cli scafollded project, but would like to understand the pattern used to determine the content of each file. Then, indeed, I would very much like to learn how to start with 3 files from scratch.