This page describes the checkout types and their respective order flows.
This is the checkout type/shop flow called "integrated checkout" in the plugin.
This is the paypal like shopflow in the plugin.
This is currently the flagship of Resurs Bank. The integration is based on an iframe that resides entirely at the side of Resurs Bank. By means, integrators only need to make customer data play with the iframe - the rest of data, including signed payments etc is handled by Resurs Bank.
There are a few ways to handle iframe related orders. This plugin should support both.