Explanation
These are two Salesforce features that can help meet the requirement of returning or reducing the quantity of activated orders. An order is a confirmation of a sale that lists products sold or services rendered to a customer, along with prices and terms of delivery or service. An order can have different statuses, such as Draft or Activated. Some features that can help manage orders are:
Zero Quantity Orders: This feature allows users to create orders with zero quantity for products that are returned or canceled by customers. Zero quantity orders can be used to track returns or cancellations without affecting inventory levels or revenue forecasts.
Reduction Orders: This feature allows users to create orders with negative quantity for products that are reduced or partially returned by customers. Reduction orders can be used to track reductions or partial returns without affecting inventory levels or revenue forecasts.

Explanation
Multiple Forecast Types must be created and activated to enable forecasting for different product lines that have different sales stages. A Forecast Type is a set of settings that define how forecasts are calculated and displayed for a specific business scenario, such as product line, territory, or revenue type. A Forecast Type can use either standard or custom opportunity fields to group and filter forecast data, such as Type, Product Family, or Territory. The Forecast tab should be visible to easily view the forecasts, as it allows users to see their forecast amounts, quotas, adjustments, and categories in a single page. Users can also drill down into forecast details, compare forecasts with other users or periods, and submit or approve forecasts from the Forecast tab.