Migrating from the old XML method to the CIM API, before I get started, just want to make sure I'm headed in the right direction.
Sorry for the vague questions - just trying to wrap my head around these new functions prior to diving in.
An authorization is followed by a prior auth capture. Capture only would be used to capture an authorization not performed through the gateway, a voice authorization for example.
I would also recommend looking at our upgrade guide to learn more about how we've combined our separately branded APIs into a single, Authorize.Net API.