>Brief summary:

> OpenVR is the architecture and API spec

> SteamVR is the software that actually implements OpenVR

> Games talk to SteamVR via the OpenVR API

> SteamVR talks to HMDs and controllers via the OpenVR Device API

> SteamVR is the piece of software that actually talks to and interfaces between software and devices. Without SteamVR, OpenVR does not do anything