Microsoft has revealed the first 13 backward-compatible original Xbox games for Xbox One. These first 13 games will be available on October 24. All the game are enhanced with 1080p resolution, higher and/or smoother framerates, and faster loading times.
Original Xbox disc will work with your Xbox One console. If you own it digitally, that will also work. Many of these games can also be purchased from the Xbox Store in digital form for $9.99.
More details available here.