The Product Cluster map in CloudBilling represents a taxonomy or categorisation of your company's services and products, in terms of your pricing and Billing needs. Product clustering usually quite closely represents the "real world" grouping of products, but of course is not limited to this.
Pricing Rules are associated to Product Clusters (and Customer Clusters), so that it is possible to define your pricing plan at both a very deep and specific level (such as unit prices for individual products), and at a higher level (such as discounts or totals across similar products). Creating a more detailed cluster tree (i.e. more nodes between the top cluster "All Products" and the bottom clusters) means you can create more detailed invoicing outputs (for instance, having subtotals at each level of the tree).
The cluster map is extremely flexible, and each cluster can have multiple children. Similarly, a cluster can also have multiple parents.
Each Product Cluster has a name that you can specify, to make managing your products as intuitive as possible. To further support this process, you are able to make use of Product Aliases. A product alias is a different name for a product cluster, and a cluster can have many aliases. The aliases are used to map incoming purchases with a matching product label. This allows for easier management and understanding of purchases that are imported, where the same product (in terms of billing needs) might be recognized under several variations or pseudonyms.