Straight from the horse’s mouth:

We’re partnering to develop a hardware and software platform within Microsoft Azure which will scale to AGI. We’ll jointly develop new Azure AI supercomputing technologies, and Microsoft will become our exclusive cloud provider—so we’ll be working hard together to further extend Microsoft Azure’s capabilities in large-scale AI systems.

Sometimes it’s hard to see the value traded in large scale investments like these. What do both sides get? With this particular investment, however, it’s pretty obvious what Microsoft is getting (Azure++) and what OpenAI is getting (an expanded R&D budget). It’s also worth noting that this is specifically focused on Artificial General Intelligence, not merely advancing the current state of the art in Machine Learning.