Azure Active Directory B2C (Azure AD B2C) is a cloud identity and access management service provided by Microsoft Azure that is specifically designed for customer-facing applications and business-to-consumer (B2C) scenarios. It allows organizations to provide authentication and authorization capabilities to external customers, partners, and users. Azure AD B2C pricing is based on a consumption model, and it includes several components to consider:

1. User Licenses: Azure AD B2C pricing is typically based on the number of monthly active users (MAUs) in your Azure AD B2C tenant. MAUs are unique users who sign in to your applications during a billing month. You are charged based on the number of MAUs in your tenant. The pricing may vary depending on the Azure AD B2C pricing tier you choose.

2. Authentication Transactions: In addition to user licenses, you may also incur charges for authentication transactions. These charges are associated with the authentication and authorization activities that occur when users sign in or interact with your applications. The cost per authentication transaction can vary depending on the type of authentication method used and the Azure AD B2C pricing tier.

3. Custom Policies: Azure AD B2C allows you to create custom identity experiences and policies for your applications. Depending on the number of custom policies and their complexity, there may be additional costs associated with custom policies.

4. External Identity Providers: If you integrate external identity providers (e.g., social identity providers like Facebook, Google, or custom identity providers), there may be separate costs associated with using these external identity providers.