Best Practices for to define list in Properties vs Modules

Hi experts

I am looking at the benefits of defining list in Properties and Modules.

Eg. The Pack Type Size members (Size) are to be tied to a SKU.

There will be inputs at Size (100g, 200g etc) and Pack Types (Small, Medium, Large) and calculations based on these inputs.

I thought I read it somewhere that it is better to define these in Modules but I can't find the writeup (or I could be imagining).  

Is there a best practise for these kind of situation?  If you have another way of doing it what is it and why ? 

Thanks.