Inventory

What is the deal with keeping count of inventory? As I understand it, if you have a product with multiple versions (I am selling tshirts, so my versions are S, M, L, XL). you just add the number of shirts in the ‘stock’ column in the Products page.

I did a few test buys and the stock counter is not reducing. It is satying the same. Am I missing something here? I bought the manual and that is how I understand it to work.

When the certain product version is not working, I’d like that version to not show up in the HTML dropdown menu, pretty much just disappear from the choices.