No, Authorize.NET is for direct payment without the user leaving your site.
However, we do not persist any credit card information to the database. As long as SSL is enabled on your site then the credit card info is encrypted across the wire from the user's web browser to your site and from there a secure ssl post is made to Authorize.NET from the web server and a response is received back with status codes indicating success or failure and reason for failure if it did fail or a transaction id if it succeeded. We do not retain any credit card information after the transaction. We do retain the billing address but we also retain that using PayPal or Google checkout because they provide that information back to us and for accounting purposes we need that customer information.
Hope that helps,
Joe