## Overview
Transactions represent the Affirm loans that are issued to the end-user. You can interact with transactions via the [Transactions API](🔗) in order to change the state of that transaction, update metadata, or retrieve details.
Transaction management
## Transactions authorization
[Transactions authorization](🔗) occurs after a user has successfully completed the Affirm checkout flow and returns back to the merchant site. Authorizing the transaction generates a unique `id` that will be used to reference the loan moving forward.
## Actions
You can integrate various transactions into your back-end order management system, where you normally fulfill orders and process payments, refunds, and cancelations.
You can use the `Transactions API` to manage transactions with the following actions:
[Read Transaction](🔗)
[Capture Transaction](🔗)
[Void Transaction](🔗)
[Refund Transaction](🔗)
[Update Transaction](🔗)
These [actions](🔗) allow you to manage transactions across various [states](🔗) including authorized, captured, voided, etc.