This stick is a palm-sized Windows 10 computer that you plug into a TV
Like a Google Chromecast, you plug the VivoStick into the HDMI port on any TV or monitor you might happen to already own.
Unlike the Google Chromecast, the Vivostick gives you a full Windows 10 desktop experience, complete with the power to run Microsoft Office or whatever other Windows software you might want to run.
The Vivostick also has two onboard USB ports for a mouse and keyboard (or anything else), or you can connect them via Bluetooth.
As you might guess, it's not extraordinarily powerful under the hood, with 2GB of memory and a modest 32GB of storage space. It'll do you just fine for watching YouTube or browsing Facebook, but it's not really recommended for playing, say, Fallout 4.
It's more than a little like Asus' own Chromebit, a similar HDMI stick that runs the Google ChromeOS operating system at a price of $85. But where Chrome OS limits you to only using a Google Chrome browser, the VivoStick gives you a full version of Windows 10.
The Asus VivoStick won't be perfect for all users, but it's another sign that Microsoft and its partners are working hard to make sure there's a Windows 10 PC for all seasons, and all markets.