What comes out of it
A design for an infrastructure that matches your requirements and fits into the systems you already run. Where it runs is open: on your site, in a co-location, in the public cloud, or spread across several of those.
How we get there
In requirement workshops we capture the requirements and the constraints for the new platform. The design follows from those, using a design method we have used for years.
The point of that method is not the shape of the document. It is that what comes out meets the requirements of everyone involved, not only the technical ones. An architecture that works technically and then fails on procurement, on operations or on data protection is not finished being designed, only finished being drawn.
The design is vendor-independent. Requirements, constraints, assumptions and risks are documented in it, and a transformation plan says in which steps the existing estate becomes the new one.
How this differs from Enterprise Architecture
Enterprise architecture looks at the IT estate as a whole, including processes and the role IT plays in the business. IT architecture designs one concrete platform inside that.
Either can be commissioned on its own. When they happen together the order gets easier: first the frame, then the platform that belongs in it.