Database Reference

A payment profile belongs to one website, contains an allowed payment-method set and can be assigned to customers or customer groups.

Relationship Why it matters
payment_profile belongs to one store_website Keeps payment rules separate between Magento websites.
payment_profile_payment_method belongs to one payment_profile Defines the payment methods the profile makes available.
payment_profile_customer assigns a profile to one customer_entity Supports customer-specific payment terms and restrictions.
payment_profile_customer_group assigns a profile to one customer_group Applies the same profile to a Magento customer group.

Use the profile editor for changes so assignment priority, conditions and validation remain consistent.