Inventory and Services
The most important object in the Inventory module is the Inventory object - it can be a Product, a Merchandise, a Service etc.
You can find more about the data structure here: Product Entity
From a UI optics this uses the classic <Browse - Add/Edit/Delete> paradigm.
Note* All prices are before taxes.
The Product Group is used to group inventory in the POS module and the TAX Category is used to calculate TAXEs (or VAT) in the POS, Sales or Purchases modules.