> ## Documentation Index
> Fetch the complete documentation index at: https://docs.valued.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Revenue Overview

> How the revenue models map to each other.

[Subscriptions](subscription) charge one or several [plans](plan) to a [customer](/core-resources/customer) on a regular basis.

A [subscription item](subscription-item) connects a subscription to one or several plans.

When your business model uses a baseline subscription and add-on features that top that up on a recurring basis, you specify for them one subscription with several subscription items. Each subscription item being a different add-on that they can add purchase on top of their subscription.

[Prices](price) specify what to charge, when and how often. Use [tiers](tiers) to define each pricing tier your product might have. Specify in each price which tier it belongs to.

Each subscription generates an [invoice](invoice) when it's time to charge a customer. It'll have as many [Invoice Items](invoice-item) as subscription items and automatic-prorations it might include.