Smartphones are essentially pocket-sized computers, packed with processing power. However, Microsoft sees its devices as actually functioning as full-blown (if somewhat underpowered) PCs, once Windows 10 for phones arrives.
At the Build developer conference, the company showed how Continuum can transform a Windows Phone into a tiny Windows PC.
Continuum adjusts the Windows 10 UI based on what is plugged into it. So if, as in the example we saw, you connect a Windows phone to a monitor via HDMI and then connect a Bluetooth keyboard and mouse, the device will switch to desktop mode.
From there it will act as a proper PC. You can run software, interact with OS using the keyboard and mouse, and enjoy a full screen experience. You can of course access everything on your phone, such as any photos, and installed apps.
Disconnect the peripherals, and the phone will (with your confirmation) switch back to tablet mode.
This capability is something that will require new hardware to really get the most from it, but it certainly looks promising.