Both words describe “the same product, but different”. They are not the same problem.
A variant is a finished thing you could put in a warehouse. A sofa in grey linen with oak legs. There is a finite list of them, and you could, in principle, count them.
A configuration is an instruction for building something. A wardrobe 2,340 mm wide with three doors, a sloped top and a hanging rail at 1,100 mm. The list is not finite, and counting it is meaningless.
How to tell which you have
Ask what happens when the customer changes one thing.
- If it swaps to another item you could have stocked → variants.
- If it changes what the workshop cuts → configurations.
A range can be both. A bed is usually variants (frame × fabric × size). A fitted wardrobe is configurations. A modular sofa is variants of modules assembled into a configuration, which is why modular ranges are the hardest thing in the catalogue.
sloped top, rail at 1 100 mm
Why the distinction costs money
Variants can be prerendered: every one of them, in advance, served as fast as any photograph. Configurations cannot, because you would be rendering a list that has no end.
Model a configuration problem as variants and the count explodes until nothing finishes. Model a variant problem as configurations and you pay for live rendering you never needed, on a page that is now slower than your competitor’s.
