The Products feature is available in the Sales Pack extension.
A product represents a good or a service. Products can be added as line items to document records such as Quote, Sales Order, Invoice, Purchase Order, and Bill. Each product can be linked to a category. Categories can be arranged in a hierarchical tree structure, where each category may include subcategories.
Product selling prices are defined in price books. You can offer the same product at different prices to different customers. Purchase prices can be specified for each supplier.
Products can be associated with tax classes. This enables automated tax application based on defined tax rules. For example, you can mark a specific product as zero-rated so that taxes are not applied to it.
With the Inventory Management feature, you can track stock availability. Products can be tracked by batch or serial numbers.
The Product entity type is available for customization in the Entity Manager – you can create new fields and link it with other entity types.

Variants
Multiple variants can be generated from a template product. For example, a shirt is available in different sizes and colors. You create only one template product, and then generate variants for each combination.
Documentation
For more information on the Products feature, see the documentation.