In the latest update of Xbox, One Microsoft introduced several new features like external storage support and Games with Gold, as well as using a real name on your Xbox Live. You can take advantage of the update from by watching the walkthrough video that explains how the new features work in real time.
How External Storage Works on Xbox One
That said, the external storage support that works with Xbox One should be USB 3.0 and size must be 256GB or freer space available. The Xbox One will recognize the drive as soon as you connect the drive with it. You will also see many options including how to format the hard drive to be used for the Xbox One. Furthermore, you can also give your device a custom name if you want.
After you have connected the hard drive with Xbox One, it will be the default storage for all new content your download. You can, even more, your previously downloaded content to your external hard drive if you want so that you can take the games with you anywhere. Up to two drives can be attached to the Xbox One at once.
The full video touches on real name supports for Xbox Live, new SmartGlass features, and an auto sign-in feature for Xbox One. Microsoft is expected to talk more about this feature for the Xbox One Live in the next week.