Variants of product exist if you have product with same name and characteristics but one or two different characteristic - size, color etc., if you have green, red, and purple shirts with size XXL and XL - you have 6 variants. You can adjust for every variant different Art.No, Store location and price. Above you enter basic product info and below you enter option name(characteristic) and option values(characteristic variants). Then you can create(manual or automatically) variants(every combination) for each option name and value combination and you can fill quantities, prices and warehouse location.