interesting all you write about this theme.

for me as a beginner there are still some questions ...

what is exactly the definition of a macro and an include? what are the advantages as well the disadvantages from each?

what are the restrictions and syntax definitions to build up them? i. e. global /local variables, underscore, ...

so when i can find this descriptions by myself anywhere, please tell me where.
otherwise i'm happy for a short explanation. thanks a lot