CB1 is an instrument of calculation; CB2 is a planning tool. It helps you to decide to expand or shrink your portfolio of products. It contains multiple CB1 sheets: one sheet for each SKU.
Screen shot of CB2 PORTFOLIO sheet: this sample company produces 25 SKUs, hence 25 CB1 sheets are made, each with the color of the product. Sales volumes and sales prices are entered in white boxes that automatically open up.