A kit can be assembled in two ways. Below, see some considerations about each of them.
Kit product without components
That's normally a product that is already structured as a kit (several components) in the store distribution center. VTEX only indicates this product, without the need for registration of its components. That is, both the price and the stock are displayed directly on the SKU kit.
Kit product with components
The kit with components is the idea of a kit product whose SKU is a "cluster" of other SKUs. This model is normally used when the kit consists of other products that are already in store, and are sold separately by origin. So, the store SKUs are selected, and the price and the stock needed for each SKU to compose 1 (one) of this kit products are settled.
For example, a kit product called Colorido is composed by other 10 SKUs. Each, with its required amount of 1 (one) SKU item to compose the kit.
So, if there is at least 1 (one) unit of each component in stock, the kit will be considered in stock, as it depends on the stock quantities registered for each of its components.
The stock quantity of a kit is the maximum number of groups that can be assembled with the amount of items available.